Sealed robot drive

ABSTRACT

A transport apparatus including a housing, a drive mounted to the housing, and at least one transport arm connected to the drive where the drive includes at least one rotor having at least one salient pole of magnetic permeable material and disposed in an isolated environment, at least one stator having at least one salient pole with corresponding coil units and disposed outside the isolated environment, where the at least one salient pole of the at least one stator and the at least one salient pole of the rotor form a closed magnetic flux circuit between the at least one rotor and the at least one stator, and at least one seal configured to isolate the isolated environment where the at least one seal is integral to the at least one stator.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a non-provisional of and claims the benefit of U.S.provisional patent application No. 61/903,813 filed on Nov. 13, 2013,the disclosure of which is incorporated herein by reference in itsentirety.

BACKGROUND 1. Field

The exemplary embodiments generally relate to robotic drives and, moreparticularly, to sealed robotic drives.

2. Brief Description of Related Developments

Generally, existing direct drive technology, which for example usespermanent magnet motors or variable reluctance motors for actuation andoptical encoders for position sensing, exhibits considerable limitationswhen, for example, the magnets, bonded components, seals and corrosivematerials of the direct drive are exposed to ultra-high vacuum and/oraggressive and corrosive environments. To limit exposure of, forexample, the magnets, bonded components, seals and corrosive materialsof the direct drive a “can-seal” is generally used.

The can-seal generally isolates a motor rotor from a corresponding motorstator via a hermetically sealed non-magnetic wall or “can”, also knownas an “isolation wall”. Canseals generally use a non-magnetic vacuumisolation wall that is located between the rotor and stator of a givenmotor actuator. This allows for the magnetic flux to flow between therotor and stator across the isolation wall. As a result, the stator canbe completely located outside the sealed environment. This may allow forsubstantially clean and reliable motor actuation implementations inapplications such as vacuum robot drives used for semiconductorapplications. The limitation of such canseals is that the size of an airgap between the rotor and stator poles may be limited by the isolationwall thickness. For example, the thickness of the isolation wall plusrunout tolerances generally imposes constraints on the minimum air gapachievable between the rotor and stator. To increase the efficiency ofthe motor the gap between the rotor and stator should be minimizedhowever, in cases where the environment sealed or otherwise isolated bythe can-seal is exposed to a high or ultra-high vacuum, the isolationwall thickness has to be large enough to provide enough structuralintegrity to substantially prevent excessive deflection (i.e. thedeflection of the isolation may interfere with the operation of themotor). As a result, the efficiency of the motor can be severelydecreased due to, for example, the need of larger air gaps between thestator and rotor when compared to robot drive solutions that do not havean isolation wall across the rotor/stator air gap.

In one aspect, “dynamic seals” may be employed to generally isolatesubstantially the entire motor from the sealed environment. The dynamicseal may be a seal that allows for a portion of the driven shaft of themotor to operate within the isolated environment. The dynamic seal canbe achieved in a number of ways including, for example, lip-seals or aferro-fluidic seal. However, these dynamic seals may possibly be asource of particle contamination (e.g. from wear and tear of the seal),high friction between the stationary and moving components, limited lifeand risk of leakage between the sealed environment and, for example, anatmospheric environment outside the sealed environment.

Other solutions for sealed drives include the stator coils being locatedwithin the sealed environment. However, in applications where the sealedenvironment operates in a high vacuum, the stator coils may outgasundesirable compounds as well as overheat. As a result, theaforementioned sealing solutions may be expensive and/or impractical.

In other aspects direct drive motors, such as the variable reluctance orswitched reluctance motors, may utilize solid rotors. However, theconventional solid rotors may have an inherent problem of core lossesdue to, for example, the effect of Eddy currents that result from therate of change of the phase currents in switched reluctance motorapplications. Other known solutions to the core loss problem include theutilization of materials with metallic ferromagnetic particles inconjunction with non-conductive particles that attempt to maintain goodmagnetic flux when compared to either a solid or laminated rotor.

It would be advantageous to have an isolation wall between the statorand rotor that minimizes the air gap between the stator and rotor. Itwould also be advantageous to have a vacuum compatible laminated rotorthat provides increased magnetic efficiency and/or precision positioncontrol.

BRIEF DESCRIPTION OF THE DRAWINGS

The foregoing aspects and other features of the disclosed embodiment areexplained in the following description, taken in connection with theaccompanying drawings, wherein:

FIGS. 1A-1D are schematic illustrations of processing apparatusincorporating aspects of the disclosed embodiment;

FIG. 1E is a schematic illustration of a transport apparatus inaccordance with aspects of the disclosed embodiment;

FIG. 1F is a schematic illustration of a control in accordance withaspects of the disclosed embodiment;

FIGS. 1G-1K are schematic illustrations of rotors for a drive motor inaccordance with aspects of the disclosed embodiment and FIG. 1L is aschematic illustration of a stator for the drive motor in accordancewith aspects of the disclosed embodiment;

FIGS. 2A and 2B illustrate portions of a drive motor in accordance withaspects of the disclosed embodiment;

FIGS. 3 and 3A are schematic illustrations of a portion of a drive motorin accordance with aspects of the disclosed embodiment;

FIG. 4 is a schematic illustration of a portion of a drive motor inaccordance with aspects of the disclosed embodiment;

FIGS. 5 and 5A are schematic illustrations of a portion of a drive motorin accordance with aspects of the disclosed embodiment;

FIG. 6 is a schematic illustration of a portion of a drive motor inaccordance with aspects of the disclosed embodiment;

FIGS. 7-15 are schematic illustrations of portions of drive motors inaccordance with aspects of the disclosed embodiment.

FIGS. 16A and 16B are schematic illustrations of stator configurationsfor drive motors in accordance with aspects of the disclosed embodiment;

FIGS. 17A and 17B are respectively schematic illustrations of a roboticarm and an extension sequence of the robotic arm in accordance withaspects of the disclosed embodiment;

FIGS. 18A and 18B are respectively schematic illustrations of a roboticarm and an extension sequence of the robotic arm in accordance withaspects of the disclosed embodiment;

FIGS. 19A and 19B are respectively schematic illustrations of a roboticarm and an extension sequence of the robotic arm in accordance withaspects of the disclosed embodiment;

FIGS. 19C and 19D are respectively schematic illustrations of a roboticarm and an extension sequence of the robotic arm in accordance withaspects of the disclosed embodiment;

FIGS. 19E and 19F are respectively schematic illustrations of a roboticarm and an extension sequence of the robotic arm in accordance withaspects of the disclosed embodiment;

FIGS. 20A-20C are respectively a partial cross-sectional view of arepresentative drive section with a sealed position feedback system,another partial perspective cross-sectional view of the drive sectionand feedback system with components omitted for clarity, and a topperspective view of elements of the position feedback system, and FIG.20D is a schematic elevation view of the position feedback system all ofwhich are in accordance with aspects of the disclosed embodiment, andFIGS. 20E-20F are respectively perspective cross-section, and expandedpartial cross-section views illustrating further features;

FIGS. 20G-20K are schematic illustrations of a drive section inaccordance with aspects of the disclosed embodiment;

FIGS. 21A and 21B are schematic diagrams of sensing elements of theposition feedback system, and FIGS. 21C and 21E are respectively apartial plan view and an enlarged plan view of a portion of an encodertrack of the position feedback system, the track having multiple bandsread by the sensing elements and capable of providing incremental and ondemand absolute position feedback, which is graphically illustrated inFIG. 21D, all of which are in accordance with aspects of the disclosedembodiment;

FIGS. 22A, 22B, 23A and 23B are schematic illustrations of a positionfeedback system and a chart of sensor output in accordance with aspectsof the disclosed embodiment;

FIGS. 24A and 24B are schematic illustrations of portions of a drivemotor in accordance with aspects of the disclosed embodiment;

FIGS. 25A, 25B and 25C are schematic illustrations of portions of adrive motor in accordance with aspects of the disclosed embodiment;

FIGS. 26A and 26B are schematic illustrations of portions of a drivemotor in accordance with aspects of the disclosed embodiment;

FIGS. 27A and 27B are schematic illustrations of portions of a drivemotor in accordance with aspects of the disclosed embodiment;

FIGS. 28A, 28B, 28C, 28D, 28E, 28F, 28G, 28H and 281 are schematicillustrations of portions of a drive motor in accordance with aspects ofthe disclosed embodiment;

FIGS. 29A, 29B and 29C are schematic illustrations of portions of adrive motor in accordance with aspects of the disclosed embodiment;

FIGS. 30A and 30B are schematic illustrations of portions of a drivemotor in accordance with aspects of the disclosed embodiment;

FIGS. 31, 32 and 33 are schematic illustrations of portions of a drivemotor in accordance with aspects of the disclosed embodiment; and

FIGS. 34, 35, 36 and 37 are schematic illustrations of portions of adrive motor in accordance with aspects of the disclosed embodiment.

DETAILED DESCRIPTION

Referring to FIGS. 1A-1D, there are shown schematic views of substrateprocessing apparatus or tools incorporating the aspects of the disclosedembodiment as disclosed further herein. Although the aspects of thedisclosed embodiment will be described with reference to the drawings,it should be understood that the aspects of the disclosed embodiment canbe embodied in many forms. In addition, any suitable size, shape or typeof elements or materials could be used.

Referring to FIGS. 1A and 1B, a processing apparatus, such as forexample a semiconductor tool station 11090 is shown in accordance withan aspect of the disclosed embodiment. Although a semiconductor tool isshown in the drawings, the aspects of the disclosed embodiment describedherein can be applied to any tool station or application employingrobotic manipulators. In this example the tool 11090 is shown as acluster tool, however the aspects of the disclosed embodiment may beapplied to any suitable tool station such as, for example, a linear toolstation such as that shown in FIGS. 1C and 1D and described in U.S. Pat.No. 8,398,355, entitled “Linearly Distributed Semiconductor WorkpieceProcessing Tool,” issued Mar. 19, 2013, the disclosure of which isincorporated by reference herein in its entirety. The tool station 11090generally includes an atmospheric front end 11000, a vacuum load lock11010 and a vacuum back end 11020. In other aspects, the tool stationmay have any suitable configuration. The components of each of the frontend 11000, load lock 11010 and back end 11020 may be connected to acontroller 11091 which may be part of any suitable control architecturesuch as, for example, a clustered architecture control. The controlsystem may be a closed loop controller having a master controller,cluster controllers and autonomous remote controllers such as thosedisclosed in U.S. Pat. No. 7,904,182 entitled “Scalable Motion ControlSystem” issued on Mar. 8, 2011 the disclosure of which is incorporatedherein by reference in its entirety. In other aspects, any suitablecontroller and/or control system may be utilized.

In one aspect, the front end 11000 generally includes load port modules11005 and a mini-environment 11060 such as for example an equipmentfront end module (EFEM). The load port modules 11005 may be boxopener/loader to tool standard (BOLTS) interfaces that conform to SEMIstandards E15.1, E47.1, E62, E19.5 or E1.9 for 300 mm load ports, frontopening or bottom opening boxes/pods and cassettes. In other aspects,the load port modules may be configured as 200 mm wafer interfaces orany other suitable substrate interfaces such as for example larger orsmaller wafers or flat panels for flat panel displays. Although two loadport modules are shown in FIG. 1A, in other aspects any suitable numberof load port modules may be incorporated into the front end 11000. Theload port modules 11005 may be configured to receive substrate carriersor cassettes 11050 from an overhead transport system, automatic guidedvehicles, person guided vehicles, rail guided vehicles or from any othersuitable transport method. The load port modules 11005 may interfacewith the mini-environment 11060 through load ports 11040. The load ports11040 may allow the passage of substrates between the substratecassettes 11050 and the mini-environment 11060. The mini-environment11060 generally includes any suitable transfer robot 11013 which mayincorporate one or more aspects of the disclosed embodiment describedherein. In one aspect the robot 11013 may be a track mounted robot suchas that described in, for example, U.S. Pat. No. 6,002,840, thedisclosure of which is incorporated by reference herein in its entirety.The mini-environment 11060 may provide a controlled, clean zone forsubstrate transfer between multiple load port modules.

The vacuum load lock 11010 may be located between and connected to themini-environment 11060 and the back end 11020. It is noted that the termvacuum as used herein may denote a high vacuum such as 10⁻⁵ Torr orbelow in which the substrate are processed. The load lock 11010generally includes atmospheric and vacuum slot valves. The slot valvesmay provide the environmental isolation employed to evacuate the loadlock after loading a substrate from the atmospheric front end and tomaintain the vacuum in the transport chamber when venting the lock withan inert gas such as nitrogen. The load lock 11010 may also include analigner 11011 for aligning a fiducial of the substrate to a desiredposition for processing. In other aspects, the vacuum load lock may belocated in any suitable location of the processing apparatus and haveany suitable configuration.

The vacuum back end 11020 generally includes a transport chamber 11025,one or more processing station(s) 11030 and any suitable transfer robot11014 which may include one or more aspects of the disclosed embodimentsdescribed herein. The transfer robot 11014 will be described below andmay be located within the transport chamber 11025 to transportsubstrates between the load lock 11010 and the various processingstations 11030. The processing stations 11030 may operate on thesubstrates through various deposition, etching, or other types ofprocesses to form electrical circuitry or other desired structure on thesubstrates. Typical processes include but are not limited to thin filmprocesses that use a vacuum such as plasma etch or other etchingprocesses, chemical vapor deposition (CVD), plasma vapor deposition(PVD), implantation such as ion implantation, metrology, rapid thermalprocessing (RTP), dry strip atomic layer deposition (ALD),oxidation/diffusion, forming of nitrides, vacuum lithography, epitaxy(EPI), wire bonder and evaporation or other thin film processes that usevacuum pressures. The processing stations 11030 are connected to thetransport chamber 11025 to allow substrates to be passed from thetransport chamber 11025 to the processing stations 11030 and vice versa.

Referring now to FIG. 1C, a schematic plan view of a linear substrateprocessing system 2010 is shown where the tool interface section 2012 ismounted to a transport chamber module 3018 so that the interface section2012 is facing generally towards (e.g. inwards) but is offset from thelongitudinal axis X of the transport chamber 3018. The transport chambermodule 3018 may be extended in any suitable direction by attaching othertransport chamber modules 3018A, 30181, 3018J to interfaces 2050, 2060,2070 as described in U.S. Pat. No. 8,398,355, previously incorporatedherein by reference. Each transport chamber module 3018, 3019A, 30181,3018J includes any suitable substrate transport 2080, which may includeone or more aspects of the disclosed embodiment described herein, fortransporting substrates throughout the processing system 2010 and intoand out of, for example, processing modules PM. As may be realized, eachchamber module may be capable of holding an isolated or controlledatmosphere (e.g. N2, clean air, vacuum).

Referring to FIG. 1D, there is shown a schematic elevation view of anexemplary processing tool 410 such as may be taken along longitudinalaxis X of the linear transport chamber 416. In the aspect of thedisclosed embodiment shown in FIG. 1D, tool interface section 12 may berepresentatively connected to the transport chamber 416. In this aspect,interface section 12 may define one end of the tool transport chamber416. As seen in FIG. 1D, the transport chamber 416 may have anotherworkpiece entry/exit station 412 for example at an opposite end frominterface station 12. In other aspects, other entry/exit stations forinserting/removing workpieces from the transport chamber may beprovided. In one aspect, interface section 12 and entry/exit station 412may allow loading and unloading of workpieces from the tool. In otheraspects, workpieces may be loaded into the tool from one end and removedfrom the other end. In one aspect, the transport chamber 416 may haveone or more transfer chamber module(s) 18B, 18 i. Each chamber modulemay be capable of holding an isolated or controlled atmosphere (e.g. N2,clean air, vacuum). As noted before, the configuration/arrangement ofthe transport chamber modules 18B, 18 i, load lock modules 56A, 56B andworkpiece stations forming the transport chamber 416 shown in FIG. 1D ismerely exemplary, and in other aspects the transport chamber may havemore or fewer modules disposed in any desired modular arrangement. Inthe aspect shown, station 412 may be a load lock. In other aspects, aload lock module may be located between the end entry/exit station(similar to station 412) or the adjoining transport chamber module(similar to module 18 i) may be configured to operate as a load lock. Asalso noted before, transport chamber modules 18B, 18 i have one or morecorresponding transport apparatus 26B, 26 i, which may include one ormore aspects of the disclosed embodiment described herein, locatedtherein. The transport apparatus 26B, 26 i of the respective transportchamber modules 18B, 18 i may cooperate to provide the linearlydistributed workpiece transport system 420 in the transport chamber. Inthis aspect, the transport apparatus 26B may have a general SCARA armconfiguration (though in other aspects the transport arms may have anyother desired arrangement such as a frog-leg configuration, telescopicconfiguration, bi-symmetric configuration, etc.). In the aspect of thedisclosed embodiment shown in FIG. 1D, the arms of the transportapparatus 26B may be arranged to provide what may be referred to as fastswap arrangement allowing the transport to quickly swap wafers from apick/place location as will also be described in further detail below.The transport arm 26B may have a suitable drive section, such as thatdescribed below, for providing each arm with any suitable number ofdegrees of freedom (e.g. independent rotation about shoulder and elbowjoints with Z axis motion). As seen in FIG. 1D, in this aspect themodules 56A, 56, 30 i may be located interstitially between transferchamber modules 18B, 18 i and may define suitable processing modules,load lock(s), buffer station(s), metrology station(s) or any otherdesired station(s). For example the interstitial modules, such as loadlocks 56A, 56 and workpiece station 30 i, may each have stationaryworkpiece supports/shelves 56S, 56S1, 56S2, 30S1, 30S2 that maycooperate with the transport arms to effect transport or workpiecesthrough the length of the transport chamber along linear axis X of thetransport chamber. By way of example, workpiece(s) may be loaded intothe transport chamber 416 by interface section 12. The workpiece(s) maybe positioned on the support(s) of load lock module 56A with thetransport arm 15 of the interface section. The workpiece(s), in loadlock module 56A, may be moved between load lock module 56A and load lockmodule 56 by the transport arm 26B in module 18B, and in a similar andconsecutive manner between load lock 56 and workpiece station 30 i witharm 26 i (in module 18 i) and between station 30 i and station 412 witharm 26 i in module 18 i. This process may be reversed in whole or inpart to move the workpiece(s) in the opposite direction. Thus, in oneaspect, workpieces may be moved in any direction along axis X and to anyposition along the transport chamber and may be loaded to and unloadedfrom any desired module (processing or otherwise) communicating with thetransport chamber. In other aspects, interstitial transport chambermodules with static workpiece supports or shelves may not be providedbetween transport chamber modules 18B, 18 i. In such aspects, transportarms of adjoining transport chamber modules may pass off workpiecesdirectly from end effector or one transport arm to end effector ofanother transport arm to move the workpiece through the transportchamber. The processing station modules may operate on the substratesthrough various deposition, etching, or other types of processes to formelectrical circuitry or other desired structure on the substrates. Theprocessing station modules are connected to the transport chambermodules to allow substrates to be passed from the transport chamber tothe processing stations and vice versa. A suitable example of aprocessing tool with similar general features to the processingapparatus depicted in FIG. 1D is described in U.S. Pat. No. 8,398,355,previously incorporated by reference in its entirety.

FIG. 1E illustrates a substrate transport apparatus 100 in accordancewith an aspect of the disclosed embodiment. It is noted that the aspectsof the disclosed embodiment described herein may be employed for vacuum(such as e.g. a high vacuum which may be 10⁻⁵ Torr and below or anyother suitable vacuum) and/or atmospheric robot applications where therotor and position feedback moving parts are isolated from theirstationary electrical counterparts (e.g. read heads and stators).Generally the aspects of the disclosed embodiment include one or moreswitched reluctance motors for operating any suitable robot arm. Themoving parts of the robot drive may be located within a sealed orotherwise isolated environment which can be a controlled environmentsuch as a vacuum environment or an atmospheric pressure environment. Anon-magnetic separation or isolation wall (which will be described ingreater detail below) made of any suitable material may be disposedbetween the moving parts of the drive (e.g. the rotor and feedbackmoving parts) and the stationary parts of the drive (e.g. the stator andthe position sensor read-heads). However, unlike conventional isolationwalls, the isolation walls described below may provide a minimized airgap between the stator and rotor that is substantially not limited by orindependent of a thickness of the isolation wall.

As may be realized, electrical components and/or permanent magnets maynot be located within the isolated environment. The drive elementslocated within the isolated environment may include one or moreferromagnetic rotors with salient (no magnets) poles, one or moreferromagnetic position feedback scales or tracks (no magnets) and one ormore drive shafts with support bearings or in other aspects withoutsupport bearings where a self-bearing motor is provided. The rotor,position feedback scales or tracks and the drive shafts may be rigidlyattached to one another and supported within the isolated environment inany suitable manner, such as with bearings or substantially withoutcontact (e.g. such as in a self-bearing motor). One or more drive shaftsof the drive assembly may be connected in any suitable manner torespective linkages of a robot arm to provide direct drive capability ofthe robot arm(s).

The stator and position sensor read heads may be located outside theisolated environment. The read heads may be any suitable type of sensorssuch as, for example, magnetic transducers. In one aspect the read headmay provide a magnetic field source and sensing of the magnetic fluxthat flows between the read head and the ferromagnetic scales or tracksdisposed within the isolated environment. In one aspect the positionfeedback read heads and tracks described herein may include a variablereluctance circuit substantially similar to that described in U.S. Pat.No. 7,834,618 entitled “Position Sensor System” and issued on Nov. 16,2010, the disclosure of which is incorporated herein by reference in itsentirety. In other aspects the position feedback apparatus may be anysuitable type of position feedback apparatus such as optical,capacitive, inductive or other type of position encoding apparatus.

The one or more stators of the drive assembly may provide a magneticfield by energizing their respective phases with the appropriatesequence and phase current magnitude resulting in a desired amount oftorque specified by any suitable controller, such as controller 190which in one aspect may be substantially similar to or incorporatedwithin controller 11091. As may be realized, reluctance motors mayexhibit nonlinearities and torque ripple, such as when in a three-phaseconfiguration. The controller 190 may be configured to account for thenonlinearities and torque ripple during operation of the robot drivesdescribed herein. Referring to FIG. 1F the control structure of thecontroller 190 may include a motion control module 190A, a communicationalgorithm module 190B and a current control module 190C arranged in, forexample, a cascaded manner. In other aspects the controller 190 mayinclude any suitable computational/control modules arranged in anysuitable manner. The motion control module 190A may be configured todetermine the commanded torques T_(cmdi) (where i=1, 2, . . . , M and Mis the total number of axes of motion of the robot drive) for the robotmotors from or based on the commanded positions for the robot motorsθ_(cmdi) and actual positions of the robot motors θ_(i) obtained fromone or more of the encoders 177 (which may include the read heads andtracks described herein).

The commutation algorithm module 190B may be configured to calculate thecommanded phase currents i_(cmdj) (where j=1, 2, . . . , N and N is thetotal number of phases of each motor) for each motor from or based onthe commanded torque T_(cmdi) for each of the robot motors. Forexemplary purposes only, a single motor 177M is shown in FIG. 1F but inother aspects any suitable number of motors may be employed. Thecommutation algorithm module 190B may be configured to determine thecommanded phase currents i_(cmdj), as a function of the commanded torqueT_(cmdi) and actual position of the motor θ_(i), from or based on aninverse of the torque-phase-position relationship of equation [1]. Asmay be realized, in one aspect a lookup table may be used to determinethe commanded phase currents i_(cmdj).

T _(i)=Σ_(j=1) ^(N) f[i _(j),θ+2π(j−1)/N],i=1, 2, . . . , M  [1]

The current controller 190C may be configured to calculate voltages forthe motor phases u_(j) to produce phase currents i_(j) that closelyfollow the commanded values of i_(cmdj). A model based approach or anyother suitable approach may be used to improve the performance of thecurrent control section of the controller 190.

Referring again to FIG. 1E, the substrate transport apparatus 100 mayinclude a direct drive motor arrangement with, for example, reluctancebased actuation (e.g. variable/switched reluctance motors) andreluctance based sensing (e.g. position feedback). In other aspects anysuitable actuators and sensors may be used. The switched reluctancemotors may substantially eliminate or otherwise reduce the presence ofmagnets and bonded joints from the rotor of the robot drive. Thereluctance based position feedback, which may be substantially similarto that described in U.S. Pat. No. 7,834,618 (the disclosure of which isincorporated herein by reference in its entirety), may provide forsensing a position of the rotor in a non-intrusive manner through, forexample, an isolation wall of the motor, such that the sensor read headis not exposed to a vacuum and/or aggressive and corrosive environmentsas will be described in greater detail below. As noted above, thesubstrate transport apparatus 100, as well as the other transportapparatus described herein, may include a controller 190 configured toreduce torque ripple of the switched reluctance motor to achieve, forexample, a smooth (e.g. without jerking) motion for direct drivesubstrate transport applications. It is noted that the motor andposition sensing arrangements described herein may be used together asdescribed herein and/or independently in combination with any othersuitable actuation or position sensing technology.

The reluctance based actuation and position sensing arrangementsdescribed herein may be used in any suitable robot drive architectureswith one or more axes of motion (e.g. degrees of freedom). One and twoaxis robot drive configurations (e.g. including but not limited toplanar/pancake drive configurations, stacked drive configurations,bearingless drive configurations and integrated drive/pumpconfigurations) which are suitable for driving single and dual endeffector robot arms are described herein for exemplary purposes only butit should be understood that the aspects of the invention describedherein are applicable to any suitable substrate transport drives havingany desired number of axes of motion for driving any suitable number ofrobot arms.

In one aspect the substrate transport apparatus 100 is shown as having alow profile planar or “pancake” style robot drive configurationsubstantially similar to those described in U.S. Pat. No. 8,008,884entitled “Substrate Processing Apparatus with Motors Integral to ChamberWalls” issued on Aug. 30, 2011 and U.S. Pat. No. 8,283,813 entitled“Robot Drive with Magnetic Spindle Bearings” issued on Oct. 9, 2012, thedisclosures of which are incorporated by reference herein in theirentireties. It is noted that due to, for example, the comparativelylarge rotor diameters and high torque capabilities the pancake styledrive configurations may offer a direct drive alternative to harmonicdrive robots for high/heavy payload applications. In other aspects anysuitable harmonic drive may be coupled to an output of the motorsdescribed herein for driving one or more robotic arms. The pancake styledrive configurations may also allow for a hollow central drive sectionwhich can accommodate a vacuum pump inlet and/or support partial or fullintegration of vacuum pumping arrangement within the robot drive, suchas in compact vacuum chambers with limited space around the robot driveor any other suitable chamber in which the robot drive is at leastpartially disposed.

The substrate transport apparatus 100 may include a reluctance drive100D having one or more stators and corresponding rotors (which in thisaspect include an outer rotor 101 and an inner rotor 102). The rotors101, 102 may be actuated by their respective stators through anenclosure or isolation wall 103 (which will be described in greaterdetail below) based on the reluctance motor principle described herein.

In one aspect, referring to FIGS. 1G and 1H which illustrate top andside cross section views of a rotor 166 in accordance with aspects ofthe disclosed embodiment, the rotor 166 may be laminated rotor. Therotor 166 may be substantially similar to the rotors described hereinand include a set of alternately stacked laminations of ferromagneticmaterial layers 167 and non-conductive layers 168 which in this exampleare stacked along an axis of rotation of the rotor (e.g. so that thelaminations extend radially from the axis of rotation) to form aradially laminated rotor where the flux flows along the laminations. Inother aspects the laminations may be arranged in any suitable manner,such as along the axis of rotation to form an axially laminated rotor asshown in FIG. 1K which illustrates a top view of the axially laminatedrotor. Here, in a manner substantially similar to that described belowwith respect to the radially laminated rotor, the axially laminatedrotor may also have ferromagnetic alternately arranged ferromagneticlayers 167′ and non-conductive layers 168′. The axially arrangedlaminations may be aligned and affixed to a hub or drive shaft 169′ inany suitable manner such as with any suitable alignment features 171 andany suitable fasteners 172 in a manner substantially similar to thatdescribed below with respect to the radially laminated rotor 166. Assuch, the aspects of the disclosed embodiment described herein may beapplied to axial flux machines and/or radial flux machines. Each layerof material may have any suitable thickness such as for example, fromabout 0.014 inch to about 0.025 inch or from about 0.35 mm to about 0.65mm. In other aspects the thickness of each lamination may be greater orless than the approximate ranges of thicknesses described above. As maybe realized the thinner that each layer of material (that the magneticfield flows through) is, the lower the Eddy current effects are on theswitched reluctance motor. The ferromagnetic material may be stamped (orformed in any suitable manner) sheets of any suitable material such as,for example, 300-series or 400-series stainless steel. Thenon-conductive layers may be formed of any suitable material such aselectric insulating vacuum compatible epoxy and/or thin sheets of vacuumcompatible or other materials including but not limited to glass,ceramic, Teflon® and polyester film tape. The stacked laminations 167,168 may be aligned for assembly in any suitable manner such as withalignment features 171 that are mounted to, for example, a hub 169. Inone aspect the alignment features 171 may include a set of pins and thehub 169 may be or form part of a drive shaft such as the drive shaftsdescribed herein so that the rotor is affixed substantially directly tothe drive shaft. The stacked laminations 167, 168 may be clamped orotherwise held together in any suitable manner such as with clampingfeatures 172. In one aspect the clamping features may be nuts configuredfor mounting on the alignment features 171. In other aspects thealignment features may be removed and replaced with clamping featuressuch as bolts that pass through the lamination to interface with the hubor drive shaft to which the rotor is mounted. In still other aspects thestacked laminations may be aligned with external fixtures and/or bondedtogether with vacuum compatible or other suitable bonding agents.Referring also to FIGS. 1I and 1J, in another aspect the stackedlaminations 167, 168 may be fully embedded (e.g. wholly enclosed on allsides and sealed) by an exterior shell 174 of any suitable material,such as for example, a vacuum compatible bonding agent in such a waythat the laminations are insulated or sealed from, for example, vacuumenvironment, corrosive environment or other environment in which therobot arm driven by the robot drive operates. Where the rotor is aninsulated rotor the ferromagnetic layers 167 may be constructed of anysuitable material such as, for example, silicon-steel separated by anysuitable electrically insulated material (which may be the same as ordifferent than the material embedding the stacked laminations 167, 168).

In another aspect, as may be realized, the switching frequency may berelatively low in direct drive applications which may allow for the useof a solid stator substantially without excessive levels of losses dueto, for example, Eddy currents. As shown in FIG. 1L the stator 206′ ofthe direct drive motor may be laminated, with laminations (e.g.alternately stacked laminations of ferromagnetic material layers 167″and non-conductive layers 168″) configured and formed generally similarto the above-described laminations of the rotor. The laminations may bepositioned with respect to the force or torque axis as described foroptimal power and minimum losses due to, for example, Eddy currents. Asmay be realized, portions of the laminated stator exterior of the sealboundary or casement (e.g. wall 103 shown in FIG. 1E containing thesealed environment) may not be sealed and may be exposed to the exterioratmosphere. Accordingly, in accordance with one aspect, the motor drivemay comprise a laminated rotor or a solid rotor motivated by switchedreluctance via a solid or laminated (in whole or in part) stator.

The drive 100D may carry any suitable robot arm 104 configured totransport, for example, semiconductor wafers, flat panels for flat paneldisplays, solar panels, reticles or any other suitable payload. In thisaspect the robot arm 104 is illustrated as a bi-symmetric type robot arm(e.g. having opposing end effectors that are linked in extension andretraction) where one of the upper arms 104U1, 104U1′ is attached to theouter rotor 101 and the other upper arm 104U2, 104U2″ is attached to theinner rotor 102. In other aspects, the robot arm may be a SCARA(selective compliant articulated robot arm) arm, telescoping arm or anyother suitable arm(s). The operation of the arms may be independent fromeach other (e.g. the extension/retraction of each arm is independentfrom other arms), may be operated through a lost motion switch (as willbe described below) or may be operably linked in any suitable way suchthat the arms share at least one common drive axis. As an example, aradial extension move of the either end effector 104E1, 104E2 of thebi-symmetric arm can be performed by substantially simultaneouslyrotating the outer rotor 101 and inner rotor 102 in opposite directionssubstantially at the same rate. Rotation of the arm 104 as a unit can beperformed by rotating the outer rotor 101 and inner rotor 102 in thesame direction as substantially the same rate.

As may be realized, the isolation wall 103 separates, for example, anatmosphere (e.g. a vacuum or other suitable controlled atmosphere) inwhich the arm 104 operates from a surrounding atmosphere (e.g. anatmospheric environment usually substantially at atmospheric pressure).It is noted that while the outer and inner rotors 101, 102 and robot arm104 are located within, for example, the vacuum environment, theactuation coils (e.g. stators) of the motors and the position sensorsare located in the atmospheric environment. The reluctance motorconfiguration of the drive 100D and/or the reluctance based feedbackposition sensors may provide for an isolation wall 103 free fromopenings, view ports or feed through arrangements. The isolation wall103 will be described in greater detail below and may be constructed ofa non-ferromagnetic or other suitable material that allows for themagnetic field associated with the actuation and position sensingarrangements to pass through the isolation wall 103.

FIGS. 2A and 2B schematically illustrate cross-sections of the exemplaryrobot drive of FIG. 1E. In one aspect, the inner and outer rotors 101,102 may be suspended from for example, the motor housing, in anysuitable manner such as by bearings 205. In other aspects, the drive100D may be a self-bearing drive where the rotors 101, 102 are suspendedsubstantially without contact in any suitable manner. Propulsion coilsor stators 206 and position sensing read heads 207, 208 may be locatedin different angular sectors on an opposite side of the isolation wall103 (e.g. in the atmospheric environment) than the respective rotors101, 102. The read heads 207 may interact with any suitable absolutescale or track 209 to provide, for example, coarse measurements ofabsolute position of the respective rotor 101, 102. Read heads 208 mayinteract with any suitable incremental scale or track 210 to determine ahigh-resolution position of the respective rotor 101, 102. The tracks209, 210 may be made of a ferromagnetic or other suitable material sothat the tracks 209, 210, for example, close or otherwise affectmagnetic circuits with the respective read heads 207, 208. Thecombination of the measurements obtained from tracks 209, 210 (absoluteand incremental) provide total high-resolution absolute positioninformation for the rotors 101, 102.

FIG. 3 is a schematic illustration of a cross section of the robot drive100D of FIG. 1E to exemplify the drive architecture. As may be realized.The stators 206, rotors 101, 102, position sensor read heads 207, 208and tracks 209, 210 may be arranged as described above with respect toFIGS. 2A and 2B. In other aspects the stators, rotors and positionsensors may have any suitable arrangement. As can be seen in FIG. 3,rotor 101 includes a first shaft, post or extension 301 to which one ofthe upper arms 104U1 (FIG. 1E) is attached and supported. Rotor 102includes a second shaft, post or extension 302 to which the other upperarm 104U2 (FIG. 1E) is attached and supported. As can be seen in FIG. 3Athe two shafts 301, 302 and drive motor arrangement may provide thedrive 100D with a hollow center for allowing an inlet of, e.g., a vacuumsource 370 (or other suitable peripheral processing device for operationof the transfer chamber in which the arm 104 operates) to be placed atthe center of the drive and/or for supporting partial or fullintegration of vacuum pumping arrangements within the robot drive. Thetwo shafts 301, 302 may also support the arm 104 for rotation of the armas a unit and/or for the extension/retraction of the end effectors104E1, 104E2 as described above.

FIG. 4 is a schematic illustration of a cross section of a robot drive100D′ which is substantially similar to drive 100D described above.However, in this aspect the drive includes a substantially centralized(e.g. located substantially concentrically within the stator/rotorarrangement) coaxial drive shaft assembly 400 which may include anysuitable number of drive shafts which may correspond to the number ofmotors included in the robot drive. In this aspect the coaxial driveshaft assembly 400 includes an inner drive shaft 402 and an outer driveshaft 401 that are supported in any suitable manner, such as bybearings. In other aspects, as noted above, the drive may be a selfbearing drive such that the drive shaft assembly 400 may be supported(e.g. via connection with the rotors) substantially without contact. Inthis aspect, the outer drive shaft 401 may be connected to the outerrotor 101 in any suitable manner, such as by drive member 401D whileinner drive shaft 402 may be connected to the inner rotor 102 in anysuitable manner such as by drive member 402D. As may be realized, thisdrive arrangement may facilitate connection of a bi-symmetric robot armassembly, a SCARA type robot arm assembly, a telescoping robot armassembly, a robot arm assembly having a lost motion switch or any othersuitable robot arm assembly that includes one or more robot arms andutilizes a coaxial drive shaft arrangement for operation of the one ormore robot arms.

FIG. 5 is a schematic illustration of a cross section of a robot drive500 which may be substantially similar to drive 100D however, in thisaspect the stator 206/rotor 101, 102 pairs may be stacked one above theother. In this aspect, as can be seen in FIG. 5, rotor 101 includes afirst shaft 301′ to which one of the upper arms 104U1 (FIG. 1E) isattached and supported. Rotor 102 includes a second shaft 302′ to whichthe other upper arm 104U2 (FIG. 1E) is attached and supported. Also, ascan be seen in FIG. 5A the two shafts 301′, 302′ and drive motorarrangement may provide a hollow center of the drive for providing aninlet of a vacuum source 370′ (or other suitable peripheral processingdevice for operation of the transfer chamber in which the arm 104operates) and/or support partial or full integration of vacuum pumpingarrangements within the robot drive in a manner substantially similar tothat described above.

FIG. 6 is a schematic illustration of a cross section of a robot drive600 which may be substantially similar to drive 100D′ however, in thisaspect the stator 206/rotor 101, 102 pairs may be stacked one above theother. In this aspect the coaxial drive shaft assembly 400′ includes aninner drive shaft 402′ and an outer drive shaft 401′ that are supportedin any suitable manner, as described above. The outer drive shaft 401′may be connected to the outer rotor 101 in any suitable manner, such asby drive member 401D′ while inner drive shaft 402′ may be connected tothe inner rotor 102 in any suitable manner such as by drive member402D′.

FIGS. 7-15 illustrate additional motor configurations in accordance withaspects of the disclosed embodiments. Referring to FIG. 7, a single axisdrive 1590 is illustrated. In this aspect a portion of the transferchamber 1500 is illustrated such that the isolation wall 103 or otherportion of the drive housing interfaces with the transfer chamber 1500housing where the interface is an isolation interface 1520. Theisolation interface may be any suitable sealed interface for isolatingenvironments such as, for example, an o-ring. Here a single drive shaft1509 is coupled to rotor 1501. The stator 1506 is positioned outside therotor 1501 so that the stator 1506 substantially surrounds the rotor1501. FIG. 8 also illustrates a single axis drive 1690 that issubstantially similar to drive 1590 shown in FIG. 7. However, the drive1690 is arranged so that the stator 1606 is disposed inside the rotor1601 such that the rotor 1601 substantially surrounds the stator 1606.

It is noted that additional drive axes (e.g. degrees of freedom) can beadded by stacking the drives either in a vertical and/or radialdirection and utilizing coaxial drive shaft arrangements to transmittorque to one or more robotic arms. Here, the rotors, stators andposition feedback read heads and tracks may be substantially the samefor each axis of motion. For example, referring to FIG. 9, a pancaketype drive 1790, substantially similar to drive 100D′ described above,is shown having coaxial drive shafts 1509A, 1509B. As can be seen inFIG. 9, the drive 1790 is arranged so that each stator 1506 is disposedoutside its respective rotor 1501, 1502 so that the stators 1506substantially surround their respective rotors 1501, 1502 and one motorsubstantially surrounds another one of the motors (e.g. one motor isnested within another of the motors). FIG. 10 illustrates a drive 1890substantially similar to drive 1790 however, in this aspect the stators1506 are disposed inside the respective rotors 1501, 1502 so that therotors 1501, 1502 substantially surround their respective stators 1506.

As may be realized a Z-axis drive may be added to any of the robotdrives described herein. For example, FIG. 11 illustrates any suitableZ-axis drive 1900 connected to drive 1790 for moving the drive 1790 inthe direction of arrow 1910 (e.g. in a direction substantially parallelwith an axis of rotation of the drive rotors. Any suitable guides, suchas rails 1930 may be provided for guiding the Z-axis movement of thedrive 1790. The Z-axis drive may include any suitable linear drivemechanism 1900D such as, for example, a ball screw drive mechanism, alinear magnetic drive, a scissor type lift or any other suitablemechanism capable of translating the drive 1790 along a linear path. Anysuitable flexible seal 1940, such as a bellows, may be provided at theinterface between the stator housing (or isolation wall 103) and drivehousing for sealing the interface between the drive and the transferchamber 1500 housing. FIG. 12 illustrates a two-axis drive 2000substantially similar to those described above where the drive motorsare vertically stacked one above the other. FIG. 13 illustrates thetwo-axis drive 2000 having Z-axis drive 1900. Again, it is noted thatwhile one and two axis drives are described herein, in other aspects thedrive may have any suitable number of drive axes. As can be seen inFIGS. 11 and 12 the vertically stacked motors are arranged so that thestators 1506 are positioned outside their respective rotors 1501, 1502.FIG. 14 illustrates a drive 2100 having a vertically stacked motorarrangement where the stators 1506 are disposed inside their respectiverotors 1501, 1502 so that the rotors 1501, 1502 substantially surroundtheir respective stators 1506.

In another aspect, the position feedback read heads and tracks may beconfigured such that the read heads are modules that can be inserted andremoved from the drive housing or isolation wall 103. For example,referring to FIG. 15, drive 2000′ is shown. Drive 2000′ may besubstantially similar to drive 2000 described above. However, the track209′ may be arranged so that the read head 207′ may interface with thetrack from above or below rather than radially (as shown in, e.g., FIG.12). The read head 207′ may be disposed in a removable read head insertor module 2110 that may be in sealed attachment to and removable fromthe isolation wall 103 or housing of the drive 2000′. Any suitable sealmay be provided at the interface between the module 2110 and theisolation wall 103 or drive housing. In other aspects, the module 2110or sensor/track separation wall can be machined into the drive housing.This drive housing can be stacked with another drive housing where astatic seal, such as an o-ring, is located in between the drivehousings. In one aspect, the track 209′ may be a combined track in thatit includes both incremental and absolute tacks. The read head 207′ maybe configured to so that both the absolute and incremental tracks areread by the read head 207′. In other aspects multiple tracks may beprovided along with one or more modules 2110 having one or moreread-heads for reading each of the incremental and absolute tracks. Instill other aspects, the removable read head module and positionfeedback track may be configured so that the read head of the module maybe positioned radially with respect to the track (as shown in FIG. 12).

As noted above, in one aspect the switched reluctance motor robot drivearrangement described herein may be part of or otherwise comprise aself-bearing drive where active and passive magnetic forces suspend therotating parts of the robot drive (and the robot arms) in place ofmechanical bearings as described in U.S. patent application Ser. No.11/769,651 entitled “Reduced-Complexity Self-Bearing Brushless DC Motor”filed on Jun. 27, 2007, the disclosure of which is incorporated hereinby reference in its entirety. In one aspect the self-bearing drives maycomprise the switched reluctance motors and sensing arrangementsdescribed herein in combination with dedicated centering/suspensionwindings. In other aspects the windings of the switched reluctancemotors may be divided into separately/independently controlled coilsections to form an integrated self-bearing motor as illustrated inFIGS. 16A and 16B.

In one aspect, as shown in FIG. 16A each motor of the robot drive 700may include three winding sets 720-722 where the winding sets extendover 3 sectors of the rotor 710. In other aspects any suitable number ofwinding sets may be provided for driving the rotor 710. Each of thewinding sets 720-722 may be driven by any suitable controller 190 in anysuitable manner such as described in U.S. patent application Ser. No.11/769,651, previously incorporated by reference herein. While windingsets 720-722 of the stator are shown substantially equally distributed(e.g. offset from each other by about 120 degrees) it should beunderstood that other offsets may also be utilized. In other aspects,the winding sets 720-722 may be arranged in a configuration that isgenerally symmetric about a desired axis but unequally distributedaround the stator perimeter.

In another aspect, as shown in FIG. 16B, the motor 701 of the robotdrive 701 may include a stator having two winding sets A and B, whereeach winding set has two winding subsets, 730, 733 and 731, 732,respectively (e.g. a four segment stator winding arrangement). The twowinding subsets in each winding set are coupled electrically and shiftedwith respect to each other by about 90 electrical degrees. As a result,when one of the two winding subsets in the pair produces pure tangentialforce the other winding subset in the pair generates pure radial force,and vice versa. In the exemplary embodiment shown, the segments of eachof the respective winding sets may be geometrically arranged at an angleof about 90°. In other aspects the geometric angular offset and theelectrical angle offset between winding segments of a respective windingset may be different from each other. Each of the winding sets A and Bmay be driven in any suitable manner by any suitable controller 190 suchas described in U.S. patent application Ser. No. 11/769,651, previouslyincorporated by reference herein.

As may be realized, in one aspect lift forces may be provided forsuspending the rotating parts (e.g. rotors 710, robot arms, positionfeedback tracks, etc.) of the drives 700, 701 in the vertical directionand/or stabilize additional degrees of freedom, such as the pitch androll angles of, e.g., the drive shafts of the drive (and hence the robotarm(s) attached to the drive shafts) may be provided by, in one aspect,dedicated windings or in other aspects passively through magneticcircuits with permanent magnets located in, e.g., the atmosphericportion of the drive system.

As described above, any suitable number and type of robot arms 104 (FIG.1E) may be attached to the drive motor arrangements described herein. Inaddition to the bi-symmetric arm 104 (FIG. 1E) other examples of armconfigurations that may be employed with the pancake type motorarrangements or the stacked motor arrangements include, but are notlimited to, the arm configurations described in U.S. patent applicationSer. No. 12/117,415 entitled “Substrate Transport Apparatus withMultiple Movable Arms Utilizing a Mechanical Switch Mechanism” filed onMay 8, 2008, the disclosure of which is incorporated by reference hereinin its entirety. For example, the arms may be derived from aconventional scara-type design, which includes an upper arm, aband-driven forearm and a band-constrained end-effector, by eliminatingthe upper arm. In the aspects illustrated in, for example, FIGS. 17A-14Bthe structural role of the upper arm may be assumed directly by one ormore rotors.

Referring to FIGS. 17A and 17B a single end effector arm driven by alinkage is shown. Referring to the kinematic diagram of FIG. 17A, inthis aspect the arm 1000 may be installed on a pair of independentlyactuated coaxial rotors such as rotors 101, 102 (see also FIG. 1E). Thearm 1000 may include a primary linkage 1003, end effector 1004 andsecondary linkage 1005. The primary linkage 1003 may be coupled to rotor101 through revolute joint 1006. End effector 1004 may be coupled toprimary linkage 1003 through revolute joint 1007, and constrained topoint radially by band arrangement 1008. The secondary linkage 1005 maybe coupled to rotor 102 and end effector 1004 through revolute joints1009 and 1010, respectively. The arm 1000 can be rotated by movingrotors 101 and 102 equally in the same direction. Radial extension ofthe arm can be controlled by moving rotors 101 and 102 simultaneously inthe opposite directions. An example radial extension move of the arm1000 may be performed in a manner substantially similar to thatdescribed in, for example, U.S. patent application Ser. No. 12/117,415(previously incorporated by reference) and is shown in a phased form inFIG. 17B.

Referring now to FIGS. 18A and 18B a single end effector arm 1100 drivenby straight bands is shown in accordance with another aspect of thedisclosed embodiment. As with arm 1000, the arm 1100 is installed on apair of independently actuated coaxial rotors 101 and 102 (see also FIG.1E). In this aspect, the arm 1100 includes linkage 1103, end effector1104 and straight band drive 1105. The linkage 1103 may be connected torotor 101 through revolute joint 1106, and coupled to rotor 102 throughband drive 1105. The end effector 1104 may be attached to linkage 1103through revolute joint 1107, and constrained to point radially by bandarrangement 1108. In this aspect, the arm 1100 can be rotated by movingrotors 101 and 102 by equal angles in the same direction. Radialextension of the arm can be controlled by moving rotors 101 and 102simultaneously in the opposite directions (e.g. by equal amounts if banddrive 1105 includes a 1:1 pulley ratio; however, any suitable ratio maybe used). An example radial extension move of the arm 1100 may beperformed in a manner substantially similar to that described in, forexample, U.S. patent application Ser. No. 12/117,415 (previouslyincorporated by reference) and is shown in a phased form in FIG. 18B.

Referring to FIGS. 19A and 19B, a single end effector arm 1200 driven bycrossed bands is illustrated in accordance with an aspect of thedisclosed embodiment. As shown in FIG. 19A, the arm 1200 may beinstalled on a pair of independently actuated coaxial rotors 101 and 102(see also FIG. 1E). In this aspect the arm 1200 includes linkage 1203,end-effector 1204 and crossed band drive 1205. Linkage 1203 may beattached to rotor 101 through revolute joint 1206, and coupled to rotor102 through crossed band drive 1205. The end effector 1204 may becoupled to linkage 1203 through revolute joint 1207, and constrained topoint radially by band arrangement 1208. In this aspect the arm 1200 canbe rotated by moving rotors 101 and 102 by equal angles in the samedirection. Radial extension of the arm can be controlled by movingrotors 101 and 102 simultaneously in the same direction by unequalamounts. An example radial extension move of the arm 1200 may beperformed in a manner substantially similar to that described in, forexample, U.S. patent application Ser. No. 12/117,415 (previouslyincorporated by reference) and is shown in a phased form in FIG. 19B.

In another aspect of the disclosed embodiment, referring to FIGS. 19Cand 19D, a dual end effector arm assembly 1300 is illustrated. The armassembly 1300 may be installed on a pair of independently actuatedcoaxial rotors 101 and 102 (see also FIG. 1E). The left-hand-side armmay include a primary linkage 1303L, end effector 1304L and secondarylinkage 1305L. The primary linkage 1303L may be coupled to rotor 102through revolute joint 1306L. The end effector 1304L may be coupled toprimary linkage 1303L through revolute joint 1307L, and constrained topoint radially by band arrangement 1308L. Secondary linkage 1305L iscoupled to rotor 101 and primary linkage 1303L through revolute joints1309L and 1310L, respectively. Similarly, the right hand side arm mayinclude primary linkage 1303R, end effector 1304R and secondary linkage1305R. The primary linkage 1303R may be coupled to rotor 102 throughrevolute joint 1306R. End effector 1304R may be coupled to primarylinkage 1303R through revolute joint 1307R, and constrained to pointradially by band arrangement 1308R. Secondary linkage 1305R may becoupled to rotor 101 and primary linkage 1303R through revolute joints1309R and 1310R, respectively. When one of the arms extends radially,the other arm rotates within a specified swing radius close to itsfolded configuration such that the linkages form a lost motionmechanism. An example radial extension move of the arm assembly 1300 maybe performed in a manner substantially similar to that described in, forexample, U.S. patent application Ser. No. 12/117,415 (previouslyincorporated by reference) and is shown in a phased form in FIG. 19D.

In another aspect of the disclosed embodiment, the arm assembly 1400illustrated in FIGS. 19E and 19F includes substantially the same typeand number of components as arm 1300. However, the arm components arearranged in a different geometric configuration, resulting insubstantially different kinematic characteristics of the lost motionmechanism. As shown in FIG. 19E, the left hand side arm includes aprimary linkage 1403L, end effector 1404L and secondary linkage 1405L.The primary linkage 3L may be coupled to rotor 101 through revolutejoint 1406L. The end effector 1404L may be coupled to primary linkage1403L through revolute joint 1407L, and constrained to point radially byband arrangement 1408L. The secondary linkage 1405L may be coupled torotor 102 and primary linkage 1403L through revolute joints 1409L and1410L, respectively. Similarly, the right hand side arm includes primarylinkage 1403R, end effector 1404R and secondary linkage 1405R. Theprimary linkage 1403R may be coupled to rotor 101 through revolute joint1406R. The end-effector 1404R may be coupled to primary linkage 1403Rthrough revolute joint 1407R, and constrained to point radially by bandarrangement 1408R. Secondary linkage 1405R may be coupled to rotor 102and primary linkage 1403R through revolute joints 1409R and 1410R,respectively. When one of the arms extends radially, the other armrotates within a specified swing radius close to its foldedconfiguration. An example radial extension move of the arm 1400 may beperformed in a manner substantially similar to that described in, forexample, U.S. patent application Ser. No. 12/117,415 (previouslyincorporated by reference) and is shown in a phased form in FIG. 19F.

Referring now to FIG. 20A, a schematic illustration of a portion of atransport apparatus drive 20200 is illustrated. The transport drive maybe employed in any suitable atmospheric or vacuum robotic transport suchas those described above. The drive may include a drive housing 20200Hhaving at least one drive shaft 20201 at least partially disposedtherein. Although one drive shaft is illustrated in FIG. 20A in otheraspects the drive may include any suitable number of drive shafts. Thedrive shaft 20201 may be mechanically suspended or magneticallysuspended within the housing 20200H in any suitable manner. In thisaspect the drive shaft is suspended within the housing with any suitablebearings 20200B but in other aspects the drive shaft may be magneticallysuspended (e.g. a self-bearing drive) in a manner substantially similarto that described in U.S. Pat. No. 8,283,813 entitled “Robot Drive withMagnetic Spindle Bearings” issued on Oct. 9, 2012, the disclosure ofwhich is incorporated by reference herein in its entirety. Each driveshaft of the drive 20200 may be driven by a respective motor 20206 whereeach motor includes stator 20206S and a rotor 20206R. The exemplaryembodiment depicted in the figures has what may be referred to as arotary drive configuration that is illustrated for purposes offacilitating description and features of the various aspects, as shownand described herein. As may be realized the features of the variousaspects illustrated with respect to the rotary drive configuration areequally applicable to a linear drive configuration. It is noted that thedrive motors described herein may be permanent magnet motors, variablereluctance motors (having at least one salient pole with correspondingcoil units and at least one respective rotor having at least one salientpole of magnetic permeable material), or any other suitable drivemotors. The stator(s) 20206S may be fixed at least partly within thehousing and the rotor(s) 20206R may be fixed in any suitable manner to arespective drive shaft 20201. In one aspect, the stator(s) 20206S may belocated in an “external” or “non-sealed” environment that is sealed froman atmosphere in which the robot arm(s) 20208 operate (the atmosphere inwhich the robot arm(s) operate is referred to herein as a “sealed”environment which may be a vacuum or any other suitable environment)through the employment of an isolation wall or barrier while therotor(s) 20206R is located within the sealed environment in a mannersubstantially similar to that described in United States provisionalpatent having attorney docket number 390P014939-US(-#1) entitled “SEALEDROBOT DRIVE” and filed on Nov. 13, 2013 the disclosure of which isincorporated by reference herein in its entirety and as will bedescribed in greater detail below. It is noted that the termsnon-ferromagnetic separation wall, seal partition or isolation wall(which will be described in greater detail below) as used herein referto a wall made of any suitable non-ferromagnetic material that may bedisposed between the moving parts of the robot drive and/or sensor andthe corresponding stationary parts of the robot drive and/or sensor.

In one aspect the housing 20200H of the drive 20200 has a substantiallydrum shaped configuration (e.g. a drum structure) having an exterior20200HE and an interior 20200HI. The housing 20200H, in one aspect, isan unitary one piece monolithic structure while, in other aspects, thehousing 20200H is an integral assembly having two or more hoops fastenedtogether in any suitable manner so as to form the drum structure of thehousing 20200H. The interior 20200HI of the housing includes a statorinterface surface 20200HS in which the stator 20206S of the variablereluctance motor 20206 is located. The stator interface surface 20200HS(and hence the housing 20200H) is configured to provide rigidity andsupport for the stator 20206S. As may be realized, the stator interfacesurface 20200HS (and hence the housing 20200H) is a datum surface thatpositions the stator 20206S (and isolation wall 2403 supported by thestator so that the stator is located in an atmospheric environmentseparate from the vacuum environment in which the rotor is located) tocontrol a gap between the stator 20206S and rotor 20206R. The housing20200H also includes a rotor interface surface 20200HR that interfaceswith and positions the rotor 20206R (e.g. the bearings 20200B arepositioned on the drive shaft 20201/rotor 20206R in a predeterminedposition and the bearings 20200B interface with the rotor interfacesurface 20200HR) so that the rotor 20206R is positioned in apredetermined position relative to the stator 20206S. As may berealized, the stator interface surface 20200HS is a datum surface forthe rotor interface surface 20200HR (and hence the rotor 20206R/driveshaft 20201) so that the rotor 20206R (and drive shaft 20201 connectedthereto) and the stator 20206S are positioned relative to and dependfrom a common datum formed by the housing 20200H. In one aspect thehousing 20200H includes a control board aperture or slot PCBS formed inthe housing 20200H and into which one or more printed circuit boards PCB(similar to PCB 20310 described below which include sensor 20203 thatinterfaces with the sensor or encoder track 20202 described below)located in the atmospheric environment and separated from the sensortrack 20202 (which is located in the vacuum environment) by a vacuumbarrier in a manner similar to that described below. The control boardaperture PCBS includes a sensor interface surface 20200HT that positionsthe sensor 20203 relative to the stator interface surface 20200HS (e.g.the common datum of the housing 20200H) in a predetermined position. Asmay be realized, the sensor track 20202 is connected to the rotor 20206Rso that the sensor track 20202 is located in a predetermined locationrelative to the rotor interface surface 20200HR. As such, the relativepositioning of the sensor interface surface 20200HT and the rotorinterface surface 20200HR with the stator interface surface 20200HSpositions and controls the gap between the sensor 20203 and the sensortrack 20202 where the stator 20206S, the rotor 20206R, the sensor 20203and the sensor track 20202 are positioned relative to and dependent fromthe common datum. In one aspect, the housing 20200H includes anysuitable slot or aperture MLS through which any suitable driveconnectors CON pass for providing power and control signals to (andfeedback signals from) the drive 20200.

Referring to FIG. 20K, it should be understood that while FIGS. 20G-20Jillustrate a drive having a single drive shaft 20201 for exemplarypurposes only, in other aspects the drive includes any suitable numberof motors having any suitable corresponding number of drive shafts. Forexample, FIG. 20K illustrates a drive 20200″ having two motors 20206A,20206B arranged in a stacked or in-line configuration. Here each motor20206A, 20206B includes a respective housing 20200H (substantiallysimilar to that described above) where the housings are connected toeach other in any suitable manner to form the multiple motor (e.g.multiple degree of freedom) drive 20200″ so that a drive shaft 20201 ofmotor 20206B extends through an aperture in a drive shaft 20201A ofmotor 20206A to form a coaxial drive spindle.

Referring also to FIG. 20B, a transport apparatus drive 20200′substantially similar to drive 20200 is illustrated having a coaxialdrive shaft arrangement with two drive shafts 20201, 20210. In thisaspect the drive shaft 20201 is driven by motor 20206 (having stator20206S and rotor 20206R) while shaft 20210 is driven by motor 20216(having stator 20216S and rotor 20216R). Here the motors are shown in astacked arrangement (e.g. in line and arranged one above or one in frontof the other). However, it should be understood that the motors 20206,20216 may have any suitable arrangement such as a side by side orconcentric arrangement. Suitable examples of motor arrangement aredescribed in U.S. Pat. No. 8,008,884 entitled “Substrate ProcessingApparatus with Motors Integral to Chamber Walls” issued on Aug. 30, 2011and U.S. Pat. No. 8,283,813 entitled “Robot Drive with Magnetic SpindleBearings” issued on Oct. 9, 2012, the disclosures of which areincorporated by reference herein in their entireties.

Referring again to FIGS. 20A and 20B and also to FIG. 20C, each driveshaft 20201 may also have mounted thereto a sensor or encoder track20202 with a position determining indicia or features that interfacewith a sensor 20203. It is noted that the sensors described herein maybe configured such that the read head portion of the sensor 20203 (e.g.the portion of the sensor to which a sensing member is mounted) aremodules that can be inserted and removed from the drive housing orisolation wall 20204 (it is noted that the isolation wall 20204 may be acommon isolation wall that also seals the drive stators from the sealedenvironment). The sensor 20203 may be fixed at least partly within thehousing 20200H in any suitable manner that allows sensing elements ormembers 20203H of the sensor 20203 to read or otherwise be influenced byone or more scales 20202S (which will be described below) for providingposition signals to any suitable controller such as controller 190(which may be substantially similar to controller 11091 describedabove). In one aspect at least a portion of the sensor 20203 may belocated in the external environment and sealed or otherwise isolatedfrom the sealed environment with the isolation wall 20204 as will bedescribed in greater detail below so that the sensor electronics and/ormagnets are disposed in the external environment while the sensor trackis disposed in the sealed environment. The sealed environment may bedifficult to monitor directly due to, for example, harsh environmentalconditions, such as vacuum environments or environments with extremetemperatures. The aspects of the disclosed embodiments described hereinprovide non-intrusive position measurement of a moving object (e.g. suchas a motor rotor, a robot arm connected to the motor or any othersuitable object) within the sealed environment.

In one aspect, referring to FIG. 20D, the sensor 20203 may utilizemagnetic circuit principles to detect the position of the encoder track20202 where the encoder track has at least one encoder scale (e.g. whereeach of the at least one encoder scale has a predetermined pitch thatmay be different than a pitch of other ones of the at least one encoderscale) located within the sealed environment. The magnetic sensingsystem illustrated in FIG. 20D is shown in a representative manner andmay be configured as a Giant Magneto Resistive sensor (GMR) or as adifferential type GMR (i.e. that senses the gradient field differentialbetween several locations, otherwise referred to as a gradiometer) aswill be described below. The sensor may include at least one magnetic orferromagnetic source 20300, the ferromagnetic encoder track 20202, andat least one magnetic sensing element or member 20203H (corresponding toeach magnetic source) disposed substantially between the magnetic sourceand the ferromagnetic track. The encoder track may be configured so thatthe track width (e.g. track face with encoding features thereon) mayextend in a plane extending radially outwards with the position encodingfeatures varying orthogonally from the track plane (e.g. up and down).In other aspects, the track width may be disposed in an axial directionparallel to the drive axis (e.g. in a rotary drive configuration thetrack face forms an annulus or cylinder surrounding the drive axis T,see for example tracks 20202S1′-S3′ in FIGS. 20E, 20F) with the encodingfeatures projecting radially (for a rotary drive) or laterally from thetrack plane. Alternatively, the track width may be disposed in a radialdirection perpendicular for the drive axis as shown in FIG. 20A. In thisaspect the at least one magnetic sensing member 20203H may have asubstantially flat (or otherwise without depending features) trackinterface that interfaces substantially directly with the track 20202but in other aspects, as described below, the at least one magneticsensor may be connected to ferromagnetic members that includeferromagnetic features that interface with corresponding features on thetrack. In one aspect the magnetic source and the at least one sensingmember 20203H may be mounted to or otherwise integrally formed on aprinted circuit board (PCB) 20310 where the printed circuit board is acommon circuit board (e.g. common to each magnetic source and each ofthe at least one sensing member). In other aspects each magnetic sourceand sensing member may be mounted to one or more respective printedcircuit boards. In one aspect the magnetic source 20300 may be apermanent magnet located within the external environment. In otheraspects the magnetic source 20300 may be any suitable source such ascoils configured to be energized to produce a magnetic field. In oneaspect the magnetic field generated by the magnetic source (the fieldlines illustrated in FIG. 20D for example purposes) depart from a northpole N (e.g. pole facing away from the track, in other aspects themagnetic poles may have any suitable orientations) of the source 20300(or in the case of energized coils in a direction determined by the flowof current through the coils), may propagate as shown, crossing the PCB20310, and flowing across the gap (e.g. between the sensing member20203H and the track 20202) through the non-ferrous isolation wall20204, to the ferromagnetic track 20202 and back to the opposing pole Sof the magnetic source 20300. As the ferromagnetic track moves relativeto the magnetic source 20300 one or more magnetic field profiles aregenerated. The magnetic field profiles may have a general shape of oneor more of a sine wave or a cosine wave. The sensing member 20203H isconfigured to detect changes to the magnetic flux that correlate withthe ferromagnetic track motion (e.g. the magnetic field profiles).

In one aspect the sensing member(s) 20203H may be any suitable giantmagneto resistive (GMR) sensing element/member capable of sensing amagnetic field in one or more locations. In other aspects the sensingmember(s) may be any suitable sensing elements capable of sensing amagnetic field. In one aspect the sensing member 20203H may beconfigured to produce a sinusoidal signal that can be used to provide aphase angle associated with, for example, an incremental (and/orabsolute) position of the ferromagnetic track 20202. In another aspect,referring to FIGS. 21A and 21B the sensing member(s) may be adifferential GMR sensing member (e.g. gradiometer) that is configured tosense a gradient field between two locations in space. The magneticsensing system may be a gradiometer as previously noted. In thegradiometer configuration, an analog output signal of each sensingmember may be proportional to the magnetic field gradient between twopoints in space. FIG. 21A illustrates a representative gradiometersensing member 20203H′ including magneto resistive elements MRE that maybe arranged to form, for example, a Wheatstone bridge that may effect adifferential encoder channel. As may be realized, the arrangement of theMRE's (e.g. R1-R4) on the gradiometer sensing member may becharacteristic of the encoding features on the encoder track andmagnetic source. FIG. 21B illustrates an exemplary gradiometer sensingmember 20203H″ in accordance with another aspect of the disclosedembodiment including magneto resistive elements MRE arranged to providetwo differential signals (e.g. sine/cosine) and a higher resolutionencoder signal. The track pitch P (FIG. 20D) and a position of themagneto resistive elements MRE on the sensing member 20203H, 20203H′,20203H″ may be matched such that differential sine and cosine outputsare obtained from each of the sensing members 20203H, 20203H′, 20203H″.

In this aspect the printed circuit board 20310 may include three sensingmembers 20503H1, 20503H2, 20503H3 (each capable of providing twodifferential signals) for obtaining position signals from aferromagnetic track 20202 (see for example, FIGS. 20C and 21C) havingthree scales 20202S. In one aspect the sensing members 20503H1, 20503H2,20503H3 (as well as the other sensors described herein) may be immovablyfixed to the circuit board. In other aspects the sensing members (aswell as the other sensors described herein) may be movably mounted tothe circuit board so that the sensing members may be adjusted relativeto their respective track 20202 scales 20202S. Referring to FIGS. 20Cand 21C-21E, in one aspect the scales 20202S may represent a 3-scaleNonius pattern that includes a master scale 20202S1, a Nonius scale202S2 and a segment scale 20202S3 but in other aspects the ferromagnetictrack may include any suitable number of scales having any suitablepositional relationship relative to one another. Here each scale 202102Smay include A respective equally spaced pattern (e.g. each scale patternmay have a respective pitch P1, P2, P3) of ferromagnetic features20202SE (e.g. slots, protrusions, etc.). For each scale 20202S there maybe a dedicated sensing member 20503H1-20503H3 that is configured toprovide analog signal outputs that substantially mimic, for example,sine and cosine waves. In one aspect one or more of the sensing members20503H1-20503H3 may be arranged at any suitable angle α1, α2 relative toanother of the sensing members 20503H1-20503H3 and/or a respective track20202S1-20202S3. In other aspects the sensing members 20503H1-20503H3may have any suitable position relationship relative to each otherand/or the respective tracks 20202S1-20202S3. As may be realized, eachscale period and number of ferromagnetic features 20202SE allows for atrack design that can be used to decode the absolute position of thetrack by using any suitable Nonius interpolation approach.

As described above, referring to FIGS. 22A and 22B, the positionfeedback system described herein may be a reluctance based sensingsystem substantially similar to that described in U.S. Pat. No.8,283,813, previously incorporated herein by reference. For example,FIG. 22A illustrates an exemplary principle of operation of thereluctance based sensing system. As can be seen in FIG. 22A a read head,such as read head 207 (the other read heads, described herein may besubstantially similar), located in, for example, the atmosphericenvironment may include a magnetic source 2205 and a sensing element2206 connected through a backing 2209. The magnetic source 2205 mayproduce a magnetic flux 2207 that propagates through the isolation wall103 and continues to the sensing element 2206 through, for example,track 209. The magnetic circuit may be closed by the backing 2209. Themagnitude of the magnetic flux 2207 may be affected by distance 2208between the source 2205 and the ferromagnetic element or track 209, andis measured by the sensing element 2206. The sensing element 2206 mayinclude one or more magnetic flux sensors, which may operate based on,for example, the Hall effect principle, magnetoresistive principle orany other suitable principle suitable for sensing the magnitude of themagnetic flux 2207.

In one aspect, one or more read heads may be utilized to interact witheach of the absolute and/or incremental track 209, 210 (see e.g. FIG.2B) to provide coarse measurements of absolute position of the rotors ofthe robot drive and/or high resolution position of the rotors of therobot drive. Referring also to FIG. 22B, an incremental sensing system2250 is illustrated, which may be used wherever read head 208 andincremental track 210 are used. In this aspect the incremental sensingsystem 2250 includes two read heads 2211, 2212 that may be substantiallysimilar to read head 207 described above. In other aspects, any suitablenumber of read heads may be used. The read heads 2211, 2212 may interactwith the incremental track 210 through the isolation wall 103. Theincremental track 210 may include multiple periodic features 2210,having any suitable size and shape to affect gradually opening andclosing the magnetic circuits of the read-heads 2211, 2212 as a functionof the relative angular position of the track 210 with respect to eachread-head 2211, 2212. In one aspect the track 210 may be incorporatedsubstantially directly into the moving component (such as a rotor) or,in other aspects, otherwise affixed to the moving component in anysuitable manner as a dedicated encoder disk. The signals generated bythe read heads 2211, 2212 may be phase shifted, and may be processed inany suitable manner by any suitable controller, such as controller 190to determine the position of the incremental track 210 within a distancethat corresponds to one period of the periodic features 2210 of theincremental track 210.

As may be realized, in addition to, for example, real-time (where realtime refers to an operational deadline from an event to a systemresponse) incremental position measurement capability, the positionfeedback systems described herein may include an additional arrangement(see read head 207 and track 209) for absolute position detection, whichallows the position feedback system (which may include controller 190 orany other suitable controller) to uniquely identify a sector of theincremental track 210 that is interacting with the read heads at anygiven point in time. This absolute position detection may be used onstart-up of the robot drive, for periodic verification of the positionmeasurement and/or on demand during operation of the robot drive. In oneaspect, referring to FIGS. 23A and 23B, the absolute track 209 mayinclude a pattern of non-uniform sectors (which may include gray-typepatterns so that one sensor changes state at a time) that are detectedby one or more read-heads 207 where each sensor may represent one bit ofan absolute position word. In this aspect, the absolute position trackillustrated in FIG. 23A may provide a 5-bit absolute position resolutionbut in other aspects, any suitable position resolution may be providedthat includes more or less than 5-bits. The corresponding 5-bit pattern,formed by the states of the read-heads (in this example there are fiveread-heads but in other aspects any suitable number of read-heads may beprovided) as the track 209 rotates is illustrated in FIG. 23B.

As described above, the environment in which the rotating parts of therobot drive are located are isolated from the environment in which thestationary parts of the robot drive are located. This isolation isthrough the use of a non-magnetic isolation wall 103 or “can seal”. Itis noted that the thickness of the isolation wall plus, e.g., runouttolerances may impose constraints on the minimum air gap achievablebetween the rotor and stator. Also, to improve motor efficiency the airgap between the rotor and stator should be minimized, however where theisolation wall is used between the rotor and stator (e.g. such as toseparate a vacuum environment from an atmospheric environment) thepressure differential on opposite sides of the isolation wall may imposea minimum thickness of the isolation wall. It is noted that theisolation wall 103 described above is integrated into the housing of therobot drive (e.g. the stator housing) however, in one aspect of thedisclosed embodiment the isolation wall 2403 (see FIGS. 24A and 24B) maybe integrally formed or otherwise integrated with the stator (e.g.separate from the drive housing) so that the stator structurallysupports the isolation wall.

As can be seen in FIG. 24A the stator 206 includes drive coils 206C andis mounted (e.g. in an atmospheric environment or other suitableenvironment) to, for example, the stator/drive housing 2405 in anysuitable manner. The stator/drive housing may have any suitable featuresor compression members that interlock to engage and bias againstcompressing sealing members so that the sealing members are held inplace for assembly and to compress the sealing members for isolatingdifferent pressures between the interior and exterior of the drivehousing. The difference in pressures may cause an isolation wall and/orhousing compression members to compress suitable seals for sealing theinside environment of the drive housing. The stator structure mayfacilitate the seal compression and sealing as described herein (seee.g. FIG. 24A). The rotor 101 is mounted within, for example, a vacuumor other suitable environment that is isolated from the, e.g.,atmospheric environment. Here an isolation wall 2403 which may be a thinmembrane mounted to or otherwise coincident with the pole or core of thestator 206 so that the stator substantially supports the isolation wall.In one aspect the isolation wall 2403 may be structurally bonded to, forexample, the inner diameter of (or any other suitable portion of) thestator in any suitable manner using any suitable bonding agent so thatthe isolation wall 2403 is integrated with (e.g. forms a unitarystructure or assembly with) the stator 206 and/or depends from thestator 206. In another aspect the isolation wall 2403 may be a coatingformed on or otherwise affixed to the pole or core of the stator 206. Inthis aspect the isolation wall 2403 may extend beyond the stator 206 tointerface with stator/drive housing 2405. As may be realized, anysuitable sealing member 2404 may be provided at the interface betweenthe isolation wall 2403 and the stator/drive housing 2405. As can beseen in FIG. 24A the isolation wall 2403 may not support any additionalstructural loading other than the pressure differential loading betweenthe vacuum and atmospheric environments (i.e. the pressure differentialloading is shared between the isolation wall and stator). FIG. 24Billustrates another example, of the isolation wall 2403′ where theisolation wall is further integrated with the stator 206. Here theisolation wall 2403′ may be substantially similar to isolation wall 2403however in this aspect the isolation wall 2403′ may substantiallyconform to (e.g. wrap around or otherwise assume the shape of) a portionthe stator 206 that extends at least partially through the stator/drivehousing 2405. In this aspect the isolation wall 2403′ is supported bythe stator 206 substantially everywhere the isolation wall interfaceswith the environment (e.g. the vacuum environment) in which the rotor islocated. Here the sealing member 2404 may lie in a different plane thandescribed above with respect to FIG. 24A for sealing the interfacebetween the isolation wall 2403′ and the stator/drive housing 2405 toisolate the isolated environment. In other aspects the sealing membermay be included in a stator to isolation wall or can interface. Forexample the sealing member may be positioned in the in or on theisolation wall.

Referring now to FIGS. 25A and 25B, a sealed drive or actuator 2500 isshown in accordance with an aspect of the disclosed embodiment. Therotor 2501 may be substantially similar to those described above and maybe located entirely within the isolated environment. The ferromagneticstator 2502 may be substantially similar to those described above andmay include a set of coil units 2503, salient poles 2505, twoferromagnetic plates 2505 a and 2505 b (e.g. stator plates) and set offerromagnetic coil cores 2506 where the coils 2503 are installed orwound. A non-magnetic isolation wall 2508 may be attached to the top andbottom stator plates 2505 a and 2505 b (to form a stator/isolation wallmodule) in any suitable manner such as with, for example, mountingscrews 2511 so that the stator plates extend beyond the isolation wallinto the sealed or otherwise isolated environment and so that the coils2506 are isolated from the sealed environment. Top and bottom sealingmember 2509 a and 2509 b, which may be any suitable sealing members suchas o-rings, may be placed along a groove or other recess along the topand bottom surfaces of the isolation wall 2508. The top and bottomstator plates 2505 a and 2505 b may have features 2507 a and 2507 b thatallow for additional stator/isolation wall modules to be stacked oneabove the other as will be described in greater detail below. In thisaspect there may be any suitable number of coils (8 coils are shown forexemplary purposes) which can be wired in pairs such that coils in eachpair are diametrically opposed to each other forming, for example, a 4phase motor. In other aspects the motor(s) may have any suitable numberof phases. The rotor poles 2504 illustrated in FIG. 25A can beconstructed of any suitable ferromagnetic material and the resultingrotor/stator pair may form a variable or switched reluctance motor. Inother aspects, the isolation wall configurations described herein may beused in Brushless DC motors with permanent magnet rotor poles or anyother suitable motor in which the rotating parts of the motor areisolated from the stationary parts of the motor. In this aspect themagnetic flux path 2512 is indicated as being along the axial directionwhich may lower Eddy current losses. In other aspects, as will bedescribed below, the flux may flow radially. As can be seen in FIGS. 25Aand 25B, the stator plates 2505 a, 2505 b extend beyond the isolationwall 2508 into the sealed environment so that the air gap 2510 betweenthe rotor pole 2504 and stator pole 2505 is not constrained by anyisolation wall (e.g. the interface is a substantially interference freeinterface and there is substantially no resistance to the magnetic fluxpath at the interface between the stator pole and the rotor pole) and itcan be as small as the mechanical tolerances between the parts allow. Asa result, the motor configuration shown in FIGS. 25A and 25B may have ahigher torque capacity than its counterpart with an isolation walldisposed in the air gap 2510 between the stator and rotor. As may berealized, the rotor 2501 torque may be generated by energizing theappropriate phase(s) using position feedback and thetorque-current-position curves of the respective rotor/stator design sothat torque ripple intrinsic to switched reluctance motors is minimizedin any suitable manner.

Referring now to FIG. 25C a two axis sealed robot drive is illustratedin accordance with aspects of the disclosed embodiment using forexample, stator/isolation wall modules described above with respect toFIGS. 25A and 25B. Again, as described above, all moving parts of themotors are located within the isolated environment. In this aspect thedrive includes a bottom plate 2514 that pilots or otherwise supports acenter stationary shaft 2515. Inner drive shaft 2517 a may be mounted toshaft 2515 in any suitable manner such as with bearings 2516 a and 2522a allowing rotational motion of inner shaft 2517 a relative tostationary shaft 2515. Rotor 2513 c may be rigidly attached to innershaft 2517 a and propelled along the rotational direction by stator 2513a by, for example, electromagnetic forces. As may be realized, thestator 2513 a and rotor 2513 c pair forms a motor that generates motiontorque to the inner shaft 2517 a. The outer drive shaft 2517 b may bemounted to the inner drive shaft 2517 a in any suitable manner such asby bearings 2516 b and 2522 b such as to provide relative rotationbetween the shafts 2517 a, 2517 b. The outer shaft 2517 b may bepropelled in a similar manner as described above such that stator 2513 band rotor 2513 d forming a second motor generates motion torque torotate the outer shaft 2517 b. The position feedback sensor(s) for theinner and outer shafts 2517 a, 2517 b, which may be substantiallysimilar to that described above, is/are positioned for tracking movementof each shaft. Here the position feedback system is illustrated as anoptical feedback system but in other aspects the feedback system may bea reluctance based feedback system as described above so that theposition feedback system operates without any feed throughs orviewports. Here the position feedback system may include an encoder disk2518 a that is affixed to the inner shaft 2517 a in any suitable mannersuch as with fastener 2519 a. A read head 2525 a (including emitter 2523a and receiver 2524 a) whose signals are routed to the outside of theisolated environment in any suitable manner across the isolationwall/stator housing 2520 a. The outer shaft position feedback operationis similar to the inner shaft described above and may include read head2525 b including emitter 2523 b and receiver 2524 b, and encoder disk2518 b (affixed to the outer shaft 2517 b). The stators 2513 a and 2513b may be mounted to isolation walls/stator housing 2520 a and 2520 b,respectively. Each isolation wall/stator housing interfaces with eachstator via a recessed feature (or equivalent interface) and any suitablestatic seal element or member such as an o-ring. The top flange 2521 andbottom plate 2514 also interface in a similar way with stator 2513 b andisolation wall/stator housing 2520 a, respectively. The inner shaft 2517a and outer shaft 2517 b constitute a two degree of freedom system thatcan be used to drive a 2 link manipulator (e.g. robot arm) locatedwithin the isolated environment. As may be realized, additional motorsmay be stacked to form drives having any suitable number of degrees offreedom. Note that there is no isolation wall between the rotor andstator ferromagnetic poles (e.g. the stator plates 2505 a, 2505 b extendbeyond the isolation wall 2508 into the isolated environment) allowingfor better torque capacity compared to conventional “Can-Seal” optionswhere the isolation wall is disposed between the stator and rotor.

Referring now to FIGS. 26A and 26B a sealed drive 2600 is shown inaccordance with aspects of the disclosed embodiment. The drive 2600 maybe substantially similar to drive 2500 described above unless otherwisenoted. In this aspect the coils 2603 of the stator 2606 are mounted in adifferent orientation than the coils 2506. However the magnetic fluxpath 2612 is substantially similar to the magnetic flux path 2512 sothat the drives 2500, 2600 operate using similar principles.

Referring to FIGS. 27A and 27B a sealed drive 2700 is shown inaccordance with aspects of the disclosed embodiment. The drive 2600 maybe substantially similar to drive 2500 described above unless otherwisenoted. In this aspect, coils 2703 a and 2703 b of the stator 2706 may bemounted in radial and axial orientations. However, the resultingmagnetic flux path 2712 is substantially similar to the flux path 2512.

Referring now to FIGS. 28A-28C a sealed robot drive 2800 is illustratedin accordance with aspects of the disclosed embodiment. The drive 2800may be substantially similar to drive 2500 unless otherwise noted. Inthis aspect, the coil units 2503 may be removably mounted substantiallydirectly on the isolation wall/stator housing 2520′ so that the numberof drive motor parts is reduced to allow for scalability of differentrotor diameters (e.g. the coil units 2503 form stator modules that maybe affixed to housings having any suitable diameter for form a statorhaving diameter corresponding to the housing diameter). As may berealized, suitable static sealing members 2809 may be disposed between,for example, flanges in each of the stator plates 2505 a, 2505 b and theisolation wall/stator housing 2520′. The direction of the magnetic flux2812 in this aspect may be substantially similar to the direction ofmagnetic flux 2512 described above. Referring also to FIG. 28D a twoaxis sealed drive assembly including stacked drives 2500 is shown. Thedrive assembly of FIG. 28D may be substantially similar to that shown inFIG. 25C unless otherwise noted. Here isolation wall/stator housing2520′ may be utilized as a common mounting structure for each stator2513 a′ and 2513b′. It is noted that the isolation wall/stator housing2520′ may also be used as a housing to support any suitable stationarycomponents of the drive such as, for example, the position feedbackapparatus 2523 a, 2524 a, 2525 a and 2523 b, 2524 b 2525 b.

As may be realized, the stator poles and rotor poles may be arranged sothat the air gap located between the poles is arranged radially oraxially with respect to an axis of rotation of the rotor. For example,in FIGS. 24A-28B the arrangement of the stator poles and rotor poles issuch that the air gap is arranged axially (e.g. so that there is aradial flow of flux through the air gap between the stator and rotorpoles). In other aspects, referring to FIGS. 28E, 28F and 28G the statorand rotors may be arranged so that the air gap between the stator androtor poles is arranged radially (e.g. so that there is an axial flow offlux 2898 through the air gap between the stator and rotor poles). Forexample, referring to FIGS. 28E and 28F, the stator coil units 2503 maybe substantially similar to those described above with respect to, forexample, FIGS. 25A-28D or any other suitable coil unit as describedherein. The coil units 2503 may be sized so that the rotor poles 2504are disposed substantially between the stator plates 2505 a, 2505 band/or between stator extensions (which will be described below) so thatthe stator plates/extensions axially overlap the rotor pole to form theradial air gap 2899. In one aspect the isolation wall/seal 2403′ may besubstantially similar to seal 2403 where the stator plates 2505 a, 2505b do not extend through the stator housing 2405. In other aspects theisolation wall may be substantially similar to isolation walls 2508and/or 2520′ described above where the stator plates extend through thestator housing/isolation wall. Referring also to FIGS. 28H and 281, therotor poles may have any suitable shape for receiving the flux from thestator poles. In this aspect the rotor poles 2504′ may be substantially“C” or channel shaped such that the rotor poles has a rotor pole core2504C′ and rotor pole plates 2504P′ extending/depending from the rotorpole core 2504C′ such that the rotor pole plates 2504P′ aresubstantially aligned with a respective one of the stator plates 2505 a,2505 b. Here there is a radial flux flow through the air gap 2899between the stator plates 2505 a, 2505 b and the rotor pole plates2504P′ but in other aspects the rotor pole core and rotor pole platesmay be arranged to provide an axial flux flow through the air gap in amanner substantially similar to that described above.

While the aspects of the disclosed embodiment described above have amagnetic flux path that is along the axial direction (longitudinal orvertical) it should be understood that the aspects of the disclosedembodiment are not limited by the direction of the flux so that eitheraxial or radial machines can be utilized. For example, FIGS. 29A-29Cillustrate a radial flux sealed drive 2900 in accordance with aspects ofthe disclosed embodiment. In this aspect, stator 2902 includes aferromagnetic stator core 2902C having stator poles 2902P, 2902P′ thatinclude coils 2903 at each stator pole. Each stator pole 2902P, 2902P′may include a respective stator pole extension 2902E, 2902E′ thatinterfaces with and extends beyond the isolation wall/stator housing2520′ in a manner substantially similar to that described above. In oneaspect the stator pole extension 2902E may be removable from therespective stator pole 2902P. Each stator pole extension 2902E may bemounted to the isolation wall/stator housing 2520′ in any suitablemanner, such as with fasteners 2511, so that each stator pole extension2902E is aligned with a respective pole 2902P of the stator 2902. Eachstator pole extension 2902E may be in substantial contact and/or closecontact (e.g. with minimal clearance) with its respective stator pole2902P such that there is substantially no resistance to the magneticflux path at the interface between the stator pole extensions and therespective stator pole. In other aspects the stator pole extensions maybe integral to (e.g. of unitary one-piece construction with) theirrespective stator poles. In this aspect, for exemplary purposes only,the stator includes a set of 8 stator modules 2902 having coils a, a′,b, b′, c, c′, d and d′, however in other aspects the stator may includeany suitable number of stator modules having any suitable number ofcoils. Here each diametrically opposed coil pair can be wired in anysuitable manner, such as for example, in series to form a 4-phasemachine. In other aspects any suitable number of phases may be provided.In this aspect the magnetic flux path 2912 is indicated along the radialdirection when phase a-a′ is energized. As can be seen in FIG. 29A, theflux 2912 flows from the stator pole 2902P, along the pole extension2902E, across the air gap 2510, reaching the rotor pole 2504A, movingalong the rotor circumference, reaching the diametrically opposite rotorpole 2504B, pole extension 2902E′ and stator pole 2902P′. The magneticflux is “closed” by a set of return paths along the stator ferromagneticcore 2902C. In one aspect the stator 2902 can be made of a stack of anysuitable laminated ferromagnetic sheets.

Referring to FIGS. 30A and 30B, in another aspect of the disclosedembodiment, which is substantially similar to that described above withrespect to FIGS. 29A-29C, the coils 2903 may be integrated with thestator pole extensions 3002E. In this aspect the stator core 2902C mayinclude a lamination stack that can be preassembled (e.g. aligned andwelded or affixed in any suitable manner which may be substantiallysimilar to that described above with respect to the laminated rotor). Inother aspects the stator core may be a solid ferromagnetic core that isformed in any suitable manner.

FIG. 31 illustrates a radial flux sealed drive 3100 in accordance withaspects of the disclosed embodiment. In this aspect the drive includes asegmented stator 3102 but is otherwise substantially similar to drive2900 described above. In other aspects the stator pole extensions 2902Emay be substantially similar to stator pole extension 3002E withintegral coils 2903. In this aspect the stator poles 2902P may not beevenly distributed (e.g. have an uneven distribution) around thecircumference of the stator 3102. The rotor poles 2504 may align withstator poles 2902P in such a way that they are not diametrically opposed(e.g. they are diametrically unopposed) to each other. Here the magneticflux path 3112 is a radial flux path that is along the plane of therotor.

FIG. 31 illustrates a sealed drive 3200 in accordance with anotheraspect of the disclosed embodiment. The drive 3200 may be substantiallysimilar to drive 3100 unless otherwise noted. Here, one coil 2903′ perphase a, b, c, d is energized but in other aspects more than one coilper phase may be energized. This aspect may allow space for larger coilssubstantially without increasing the stack height of the stator 2902,for example, by leveraging the arc length of the segmented statorelements. In other aspects the coil locations of for example, FIGS. 31and 32 may be combined to maximize the utilization of coil space asillustrated in FIG. 33.

In another aspect of the disclosed embodiment a sealed drive 3400 may beprovided where the isolation wall is structurally supported on, forexample, the isolated environment side of the isolation wall by anysuitable seal supporting member. For example, referring to FIG. 34 adrive 3400 substantially similar to the drives described above withrespect to FIGS. 25A-33 is illustrated where stator pole extensions areutilized. In this aspect the drive 3400 includes a seal casing orisolation wall 3451 that intervenes or is otherwise disposed between thestator poles 3503P and the stator pole extensions 3503E. In this aspectany suitable seal supporting member 3450 may be disposed within theisolated environment. The seal supporting member 3450 may be constructedof any suitable material and have any suitable shape. The sealsupporting member 3450 may be configured to house a set of ferromagneticstator pole extensions 3503E such that the stator pole extensions 3450Eare substantially aligned with their respective stator poles 3503P. Inone aspect the stator pole extensions may be embedded within or integralto (e.g. forms a one piece unitary member with) the seal supportingmember. In other aspects the stator pole extension may be removablymounted within or to the seal supporting member. It is noted that thestator pole extensions are located within the isolated environment andseparated from their respective stator poles (which are located in theatmospheric environment) by the isolation wall 3451 which is anultra-thin can seal.

In one aspect one or more ultra-thin can seal(s) or isolation wall(s)3451 may be disposed around the outside perimeter of the seal supportingmember 3450 such that the isolation wall is disposed between andseparates the stator pole extensions from their respective stator poles(e.g. the isolation wall 3451 penetrates the stator). As may berealized, there may be no motion between the stator pole extensions andtheir respective stator poles, as well as no motion between theisolation wall and the stator. In one aspect the isolation wall 3451 maybe one or more non-magnetic cylindrical sleeves of any suitable materialsuch as stainless steel or any other suitable material capable ofproviding a seal in, for example, a vacuum or other isolatedenvironment. In other aspects the isolation wall may be formed byapplying a coating or other membrane to the seal supportingmember/stator pole extension assembly. Here the non-magnetic sleeves mayprovide a seal for each stator pole for a respective motor in the drive3400. For example, the magnetic sleeve may circumscribe the outerperimeter of the seal supporting member at a level of the sealsupporting member that is coincident with the stator poles of arespective motor such that the stator poles belonging to common motoralso share a common isolation wall. Where the drive 3400 includes morethan one motor, such as in a stacked arrangement, an isolation wall maybe provided for each motor such that the isolation walls form bands thatare disposed one above the other on the outside perimeter of the sealsupporting member as will be described below. In other aspects theisolation wall may be common to two or more motors of the driveassembly. In still other aspects the isolation wall may be a sectionedwall where each stator pole may have a corresponding isolation wallsection (e.g. disposed on the seal supporting member) that is distinctfrom the isolation wall of other stator poles.

The isolation wall 3451 may be ultra-thin and have a thickness of about30 μm while in other aspects the thickness of the isolation wall 3451may be more or less than 30 μm. As noted above, the isolation wall 3451is disposed around the outside perimeter of the seal supporting member3450 which structurally supports the isolation wall 3451 as the pressurewithin the isolated environment departs from an atmospheric pressure.For example, as the pressure difference builds between, for example, avacuum pressure within the isolated environment and the atmosphericpressure outside the isolated environment, the isolation wall 3451 ispushed against the seal supporting member 3450 by the pressuredifferential such that the seal supporting member 3450 and the statorpole extension element 3503E substantially prevents the isolation wall3451 from collapsing. It is noted that while the magnetic flux betweenthe stator and the rotor faces the isolation wall (disposed between thestator poles and stator pole extensions) as well as the rotor/stator airgap, the net losses are minimized by the small gap between the statorand rotor as well as the negligible thickness of the isolation wall.

Referring to FIG. 35 a stackable motor module 3400M is illustrated inaccordance with an aspect of the disclosed embodiment. FIG. 35illustrates a cross sectional view A-A of the drive 3400. In one aspectthe stackable motor module 3400M may include an array of stator poleextensions 3503E housed within a ring-shaped (or other suitable shape)seal supporting structure 3450′ that has a top 3450T′ and a bottom3450B′ surface (it is noted that the terms top and bottom are used forexemplary purposes only and in other aspects any suitable spatial termsmay be assigned to surfaces 3450T′, 3450B′) and an isolation wall 3451affixed to the seal supporting surface. Static seal members 2509 may bedisposed on each of the surfaces 3450T′, 3450B′ such that when themodules 3400M are stacked substantially no air flow exists between theisolated environment and the atmospheric environment. An isolation wall3451 may be disposed around and affixed to the outer perimeter of theseal support member 3450′ in any suitable manner such that any gapsbetween the stator pole extension 3503E and the seal support member3450′ are covered by the isolation wall. Static seal members 3509′ mayalso be disposed between the isolation wall 3451 and the seal supportmember 3450′ to provide a seal between the isolation wall and the sealsupport member. In this aspect the stator 3503 may be positioned aroundthe motor module 3400M and the rotor 3501 may be positioned within themotor module 3400M to form a drive motor. In other aspects, the motormodule 3400M may also include the stator 3503 (which may be affixed tothe seal support member and/or the isolation wall in any suitablemanner. In still other aspects the rotor 2501 may also be included inthe motor module 3400M.

FIG. 36 illustrates the motor modules 3400M1, 3400M2 (which aresubstantially similar to motor module 3400M) stacked one above the otherto form a two axis of movement drive. As can be seen in FIG. 36 eachmodule 3400M1, 3400M2 includes a respective isolation wall 3451 suchthat the isolation walls for bands arranged one above the other along acombined length of the seal supporting structures 3450′ (which may formthe seal supporting structure 3450). Here, the number of static sealmembers 3509′ between the isolation walls 3451 and the respective sealsupporting members 3450 is dependent on the number of drive axes. Inanother aspect, as shown in FIG. 37, the number of static seal membersmay be independent of the number of drive axes. For example, FIG. 37illustrates a stacked two axis of movement drive substantially similarto that shown in FIG. 36. However, here a unitary or one piece isolationwall 3451′ (e.g. a continuous seal casing) is provided on the outerperimeter of the seal supporting members 3450′ such that the stackedseal supporting members 3450 share a common isolation wall 3451′ and thecommon isolation wall 3451′ extends over one or more motors. In thisaspect it is also noted that isolation wall also provides for sealingthe interface between the stacked seal support members so that the sealmember(s) 3509 disposed between the seal support members may be omitted.

In accordance with one or more aspects of the disclosed embodiment atransport apparatus is provided. The transport apparatus includes ahousing, drive mounted to the housing and at least one transport armconnected to the drive. The drive includes at least one rotor having atleast one salient pole of magnetic permeable material and disposed in anisolated environment, at least one stator having at least one salientpole with corresponding coil units and disposed outside the isolatedenvironment where the at least one salient pole of the at least onestator the at least one salient pole of the rotor form a closed magneticflux circuit between the at least one rotor and the at least one stator,and at least one seal configured to isolate the isolated environmentwhere the at least one seal is integral to the at least one stator.

In accordance with one or more aspects of the disclosed embodiment theat least one seal comprises a membrane mounted to the at least onestator.

In accordance with one or more aspects of the disclosed embodiment theat least one seal depends from the at least one stator.

In accordance with one or more aspects of the disclosed embodiment theat least one stator structurally supports the at least one seal.

In accordance with one or more aspects of the disclosed embodiment theat least one seal conforms to a shape of the at least one stator.

In accordance with one or more aspects of the disclosed embodimentwherein the at least one rotor and the at least one stator form stackedmotors or motors that are radially nested one inside the other.

In accordance with one or more aspects of the disclosed embodiment thetransport apparatus further includes at least one reluctance basedencoder track disposed on each of the at least one rotor and at leastone reluctance based position feedback sensor configured to interfacewith the at least one reluctance based encoder track.

In accordance with one or more aspects of the disclosed embodiment theat least one rotor is coupled to a coaxial drive shaft arrangement fordriving the at least one transport arm.

In accordance with one or more aspects of the disclosed embodiment theat least one stator is a segmented stator.

In accordance with one or more aspects of the disclosed embodiment thedrive is configured as an axial flux flow drive or a radial flux flowdrive.

In accordance with one or more aspects of the disclosed embodiment theat least one rotor includes laminated salient poles.

In accordance with one or more aspects of the disclosed embodiment theat least one stator includes laminated salient poles.

In accordance with one or more aspects of the disclosed embodiment theat least one rotor includes a drive member interface, the drive furtherincluding a drive transmission member interfaced with the at least onerotor at the drive member interface such that the drive memberinterfaces with the laminated salient poles and fixes the laminatedsalient poles to the drive member.

In accordance with one or more aspects of the disclosed embodiment thelaminated salient poles are fixed to the drive member so that thelaminated salient poles are arranged axially relative to the drivemember.

In accordance with one or more aspects of the disclosed embodiment thelaminated salient poles are fixed to the drive member so that thelaminated salient poles are arranged radially relative to the drivemember.

In accordance with one or more aspects of the disclosed embodiment thedrive includes a z-axis drive motor connected to the housing.

In accordance with one or more aspects of the disclosed embodimenttransport apparatus is provided. The transport apparatus includes ahousing, a drive mounted to the housing and at least one transport armconnected to the drive. The drive includes at least one rotor having atleast one salient pole of magnetic permeable material and being locatedwithin an isolated environment, at least one stator having salientstator poles with respective coil units and being located outside theisolated environment, at least one salient stator pole extensiondisposed within the isolated environment and aligned with a respectsalient stator pole so that the at least one salient stator poleextension and the at least one salient pole of the rotor form a closedmagnetic flux circuit between the at least one stator and the at leastone rotor, and at least one seal disposed between each stator pole and arespective salient stator pole extension where the at least one seal isconfigured to isolate the isolated environment.

In accordance with one or more aspects of the disclosed embodiment thedrive further includes a seal support member having an inner surfacedisposed in the isolated environment and an outer surface facing awayfrom the isolated environment, where the at least one seal is disposedon or adjacent the outer surface and the seal support surface isconfigured to structurally support the at least one seal.

In accordance with one or more aspects of the disclosed embodiment theseal support member is configured to house the at least one salientstator pole extension.

In accordance with one or more aspects of the disclosed embodiment theat least one stator and the at least one rotor form stacked motors andthe at least one seal is common to each of the stacked motors.

In accordance with one or more aspects of the disclosed embodiment theat least one stator and the at least one rotor form a stack of motorsand the at least one seal includes a seal for each motor that isdistinct from seals of other motors in the stack of motors.

In accordance with one or more aspects of the disclosed embodiment theat least one salient stator pole extension and the at least one rotorare positioned such that the at least one salient stator pole extensionand the at least one rotor have an obstructionless interface.

In accordance with one or more aspects of the disclosed embodiment eachstator and respective rotor form a motor module configured to be stackedwith other motor modules.

In accordance with one or more aspects of the disclosed embodiment thedrive is configured as an axial flux flow drive or a radial flux flowdrive.

In accordance with one or more aspects of the disclosed embodiment theat least one rotor includes laminated salient poles.

In accordance with one or more aspects of the disclosed embodiment theat least one rotor includes a drive member interface, the drive furtherincluding a drive transmission member interfaced with the at least onerotor at the drive member interface such that the drive memberinterfaces with the laminated salient poles and fixes the laminatedsalient poles to the drive member.

In accordance with one or more aspects of the disclosed embodiment thelaminated salient poles are fixed to the drive member so that thelaminated salient poles are arranged axially relative to the drivemember.

In accordance with one or more aspects of the disclosed embodiment thelaminated salient poles are fixed to the drive member so that thelaminated salient poles are arranged radially relative to the drivemember.

In accordance with one or more aspects of the disclosed embodiment theat least one stator includes laminated salient poles.

In accordance with one or more aspects of the disclosed embodiment thedrive includes a z-axis drive motor connected to the housing.

In accordance with one or more aspects of the disclosed embodiment thetransport apparatus further includes at least one reluctance basedencoder track disposed on each of the at least one rotor and at leastone reluctance based position feedback sensor configured to interfacewith the at least one reluctance based encoder track.

In accordance with one or more aspects of the disclosed embodiment theat least one rotor is coupled to a coaxial drive shaft arrangement fordriving the at least one transport arm.

In accordance with one or more aspects of the disclosed embodiment atransport apparatus is provided. The transport apparatus includes ahousing, a drive mounted to the housing and at least one transport armconnected to the drive. The drive includes at least one rotor having atleast one salient pole of magnetic permeable material, at least onestator including a stator core, a salient top plate, a salient bottomplate and a coil unit associated with each salient top and bottom platepair where the salient top plate and salient bottom plate are connectedto and spaced apart by the stator core and configured to interface withthe at least one salient pole of the at least one rotor to form a closedmagnetic flux circuit between the at least one stator and the at leastone rotor, and an isolation wall disposed between the top plate andbottom plate where the isolation wall is configured to isolate thestator core from an isolated environment in which the at least onetransport arm operates.

In accordance with one or more aspects of the disclosed embodiment eachrotor and respective stator are configured as a motor module, the motormodule being configured to interface with other motor modules to form adrive having stacked motors.

In accordance with one or more aspects of the disclosed embodiment thedrive is configured as an axial flux flow drive or a radial flux flowdrive.

In accordance with one or more aspects of the disclosed embodiment thedrive includes a z-axis drive motor connected to the housing.

In accordance with one or more aspects of the disclosed embodiment thetransport apparatus further includes at least one reluctance basedencoder track disposed on each of the at least one rotor and at leastone reluctance based position feedback sensor configured to interfacewith the at least one reluctance based encoder track.

In accordance with one or more aspects of the disclosed embodiment theat least one rotor is coupled to a coaxial drive shaft arrangement fordriving the at least one transport arm.

In accordance with one or more aspects of the disclosed embodiment atransport apparatus is provided. The transport apparatus includes ahousing, a drive mounted to the housing and at least one transport armconnected to the drive. The drive includes at least one laminated rotorhaving laminated salient poles of magnetic permeable material disposedin an isolated environment where the at least one laminated rotor isisolated from the isolated environment. The drive further includes atleast one stator having at least one salient pole with respective coilunits disposed outside the isolated environment such that the at leastone salient pole of the at least one laminated rotor and the salientpole of the at least one stator form a closed magnetic flux circuitbetween the at least one stator and the at least one rotor, and at leastone seal configured to isolate the isolated environment.

In accordance with one or more aspects of the disclosed embodiment theat least one laminated rotor includes a drive member interface, thedrive further including a drive transmission member interfaced with theat least one rotor at the drive transmission member interface such thatthe drive member interfaces with the laminated salient poles and fixesthe laminated salient poles to the drive transmission member.

In accordance with one or more aspects of the disclosed embodiment thelaminated salient poles are fixed to the drive transmission member sothat the laminated salient poles are arranged axially relative to thedrive transmission member.

In accordance with one or more aspects of the disclosed embodiment thelaminated salient poles are fixed to the drive transmission member sothat the laminated salient poles are arranged radially relative to thedrive transmission member.

In accordance with one or more aspects of the disclosed embodiment theat least one laminated rotor is embedded in an insulator that isconfigured to isolate the at least one laminated rotor from the isolatedenvironment.

In accordance with one or more aspects of the disclosed embodiment theat least one seal is integral to the at least one stator.

In accordance with one or more aspects of the disclosed embodiment theat least one seal comprises a membrane mounted to the at least onestator.

In accordance with one or more aspects of the disclosed embodiment theat least one seal depends from the at least one stator.

In accordance with one or more aspects of the disclosed embodiment theat least one stator structurally supports the at least one seal.

In accordance with one or more aspects of the disclosed embodiment theat least one seal conforms to a shape of the at least one stator.

In accordance with one or more aspects of the disclosed embodiment theat least one stator includes a stator core, a top plate and a bottomplate where the top plate and bottom plate form a salient pole and areconnected to and spaced apart by the stator core and configured tointerface with the at least one laminated rotor, and the at least oneseal is between the top plate and bottom plate and configured to isolatethe stator core from an isolated environment in which the at least onetransport arm operates.

In accordance with one or more aspects of the disclosed embodiment thedrive further includes at least one salient stator pole extensiondisposed within the isolated environment and aligned with a respectivesalient pole of the stator, where the at least one seal is disposedbetween each salient pole of the stator and a respective salient statorpole extension.

In accordance with one or more aspects of the disclosed embodiment thedrive further includes a seal support member having an inner surfacedisposed in the isolated environment and an outer surface facing awayfrom the isolated environment, where the at least one seal is disposedon or adjacent the outer surface and the seal support surface isconfigured to structurally support the at least one seal.

In accordance with one or more aspects of the disclosed embodiment theseal support member is configured to house the at least one salientstator pole extension.

In accordance with one or more aspects of the disclosed embodiment atransport apparatus is provided. The transport apparatus includes ahousing, a drive mounted to the housing and at least one transport armconnected to the drive. The drive includes at least one vacuumcompatible laminated rotor having laminated salient rotor poles ofmagnetic permeable material and being disposed in an isolatedenvironment where the at least one vacuum compatible laminated rotorincludes a set of alternately stacked laminations of ferromagneticlayers and non-conductive layers. The drive further includes at leastone stator having at least one salient stator pole with respective coilunits disposed outside the isolated environment where each laminatedsalient rotor poles when interfaced with the at least one salient rotorpole form a closed magnetic flux circuit between the at least one vacuumcompatible laminated rotor and the at least one stator, and at least oneseal configured to isolate the isolated environment.

In accordance with one or more aspects of the disclosed embodiment thedrive includes at least one drive shaft and retaining members configuredto mount the at least one vacuum compatible laminated rotor to the atleast one drive shaft and clamp the alternately stacked laminationstogether.

In accordance with one or more aspects of the disclosed embodiment thealternately stacked laminations are bonded together.

In accordance with one or more aspects of the disclosed embodiment theat least one seal is integral to the at least one stator.

In accordance with one or more aspects of the disclosed embodiment theat least one seal comprises a membrane mounted to the at least onestator.

In accordance with one or more aspects of the disclosed embodiment theat least one seal depends from the at least one stator.

In accordance with one or more aspects of the disclosed embodiment theat least one stator structurally supports the at least one seal.

In accordance with one or more aspects of the disclosed embodiment theat least one seal conforms to a shape of the at least one stator.

In accordance with one or more aspects of the disclosed embodiment theat least one stator includes a stator core, a top plate and a bottomplate where the top plate and bottom plate form a salient stator poleand are connected to and spaced apart by the stator core and configuredto interface with the at least one vacuum compatible laminated rotor,and the at least one seal is between the top plate and bottom plate andconfigured to isolate the stator core from an isolated environment inwhich the at least one transport arm operates.

In accordance with one or more aspects of the disclosed embodiment thedrive further includes at least one salient stator pole extensiondisposed within the isolated environment and aligned with a respectivesalient stator pole, where the at least one seal is disposed betweeneach salient stator pole and a respective salient stator pole extension.

In accordance with one or more aspects of the disclosed embodiment thedrive further includes a seal support member having an inner surfacedisposed in the isolated environment and an outer surface facing awayfrom the isolated environment, where the at least one seal is disposedon or adjacent the outer surface and the seal support surface isconfigured to structurally support the at least one seal.

In accordance with one or more aspects of the disclosed embodiment theseal support member is configured to house the at least one salientstator pole extension.

In accordance with one or more aspects of the disclosed embodiment theat least one seal is integrated with a structure of the at least onestator.

In accordance with one or more aspects of the disclosed embodiment theat least one seal is supported by a structure of the at least onestator.

In accordance with one or more aspects of the disclosed embodiment avariable reluctance motor assembly includes a casing having a drumstructure, a stator mounted within the drum structure, and a rotormounted within the drum structure and interfaced with the stator, wherethe casing includes a common datum that forms a stator interface surfaceconfigured to support the stator and position the stator and rotorrelative to each other for effecting a predetermined gap between thestator and rotor.

In accordance with one or more aspects of the disclosed embodiment thevariable reluctance motor assembly further includes an isolation wall2403 supported by the stator such that the isolation wall is located ina predetermined position relative to the common datum and the rotor.

In accordance with one or more aspects of the disclosed embodiment thevariable reluctance motor assembly further includes a sensor trackconnected to the rotor and a sensor mounted to the casing in apredetermined position relative to the common datum so as to effect apredetermined gap between the sensor and sensor track, where the stator,rotor, sensor and sensor track are positioned relative to and dependfrom the common datum.

In accordance with one or more aspects of the disclosed the casing is amonolithic member that forms the drum structure and into which slots areformed for one or more of sensors, control boards and drive connectors.

In accordance with one or more aspects of the disclosed embodiment thecasing is an integral assembly formed by two or more hoop membersconnected to each other to form the drum structure.

In accordance with one or more aspects of the disclosed embodiment avariable reluctance motor casing includes an exterior surface, aninterior surface where the exterior and interior surfaces form a drumstructure, the interior surface including a common datum that forms astator interface surface configured to support a stator and position thestator and a rotor relative to each within the casing to effect apredetermined gap between the stator and rotor.

In accordance with one or more aspects of the disclosed embodiment theinterior surface includes a rotor interface surface positioned relativeto the common datum so that the stator and rotor are positioned from andsupported by the common datum.

In accordance with one or more aspects of the disclosed embodiment thedrum structure includes a sensor interface surface configured to supporta sensor relative to a sensor track connected to the rotor and effect apredetermined gap between the sensor and sensor track, where the sensorinterface surface is positioned relative to the common datum so that thestator, rotor and sensor are positioned from and supported by the commondatum.

In accordance with one or more aspects of the disclosed embodiment, thesensor interface surface is formed as a slot within the drum structure.

In accordance with one or more aspects of the disclosed embodiment, theslot is configured to house the sensor and a motor control board.

In accordance with one or more aspects of the disclosed the drumstructure is a monolithic member into which slots are formed for one ormore of sensors, control boards and drive connectors.

In accordance with one or more aspects of the disclosed embodiment thedrum structure is an integral assembly formed by two or more hoopmembers connected to each other.

It should be understood that the foregoing description is onlyillustrative of the aspects of the disclosed embodiment. Variousalternatives and modifications can be devised by those skilled in theart without departing from the aspects of the disclosed embodiment.Accordingly, the aspects of the disclosed embodiment are intended toembrace all such alternatives, modifications and variances that fallwithin the scope of the appended claims. Further, the mere fact thatdifferent features are recited in mutually different dependent orindependent claims does not indicate that a combination of thesefeatures cannot be advantageously used, such a combination remainingwithin the scope of the aspects of the invention.

What is claimed is:
 1. A transport apparatus comprising: a housing; adrive mounted to the housing; and at least one transport arm connectedto the drive; where the drive includes at least one rotor having atleast one salient pole of magnetic permeable material and disposed in anisolated environment; at least one stator having at least one salientpole with corresponding coil units and disposed outside the isolatedenvironment; where the at least one salient pole of the at least onestator and the at least one salient pole of the rotor form a closedmagnetic flux circuit between the at least one rotor and the at leastone stator; and at least one seal configured to isolate the isolatedenvironment where the at least one seal is integral to the at least onestator.
 2. The transport apparatus of claim 1, wherein the at least oneseal comprises a membrane mounted to the at least one stator.
 3. Thetransport apparatus of claim 1, wherein the at least one seal dependsfrom the at least one stator.
 4. The transport apparatus of claim 1,wherein the at least one stator structurally supports the at least oneseal.
 5. The transport apparatus of claim 1, wherein the at least oneseal conforms to a shape of the at least one stator.
 6. The transportapparatus of claim 1, wherein the at least one rotor and the at leastone stator form stacked motors or motors that are radially nested oneinside the other.
 7. The transport apparatus of claim 1, furthercomprising at least one reluctance based encoder track disposed on eachof the at least one rotor and at least one reluctance based positionfeedback sensor configured to interface with the at least one reluctancebased encoder track.
 8. The transport apparatus of claim 1, wherein theat least one rotor is coupled to a coaxial drive shaft arrangement fordriving the at least one transport arm.
 9. The transport apparatus ofclaim 1, wherein the at least one stator is a segmented stator.
 10. Thetransport apparatus of claim 1, wherein the drive is configured as anaxial flux flow drive or a radial flux flow drive.
 11. The transportapparatus of claim 1, wherein the at least one stator includes laminatedsalient poles.
 12. The transport apparatus of claim 1, wherein the atleast one rotor includes laminated salient poles.
 13. The transportapparatus of claim 12, wherein the at least one rotor includes a drivemember interface, and the drive further includes a drive transmissionmember interfaced with the at least one rotor at the drive memberinterface such that the drive transmission member interfaces with thelaminated salient poles and fixes the laminated salient poles to thedrive transmission member.
 14. The transport apparatus of claim 13,wherein the laminated salient poles are fixed to the drive transmissionmember so that the laminated salient poles are arranged axially relativeto the drive transmission member.
 15. The transport apparatus of claim13, wherein the laminated salient poles are fixed to the drivetransmission member so that the laminated salient poles are arrangedradially relative to the drive transmission member.
 16. The transportapparatus of claim 1, wherein the drive includes a z-axis drive motorconnected to the housing.
 17. A transport apparatus comprising: ahousing; a drive mounted to the housing; and at least one transport armconnected to the drive; where the drive includes at least one rotorhaving at least one salient pole of magnetic permeable material andbeing located within an isolated environment; at least one stator havingsalient stator poles with respective coil units and being locatedoutside the isolated environment; at least one salient stator poleextension disposed within the isolated environment and aligned with arespect salient stator pole so that the at least one salient stator poleextension and the at least one salient pole of the rotor form a closedmagnetic flux circuit between the at least one stator and the at leastone rotor; and at least one seal disposed between each stator pole and arespective salient stator pole extension where the at least one seal isconfigured to isolate the isolated environment.
 18. The transportapparatus of claim 17, wherein the drive further includes a seal supportmember having an inner surface disposed in the isolated environment andan outer surface facing away from the isolated environment, where the atleast one seal is disposed on or adjacent the outer surface and the sealsupport surface is configured to structurally support the at least oneseal.
 19. The transport apparatus of claim 18, wherein the seal supportmember is configured to house the at least one salient stator poleextension.
 20. The transport apparatus of claim 17, wherein the at leastone stator and the at least one rotor form stacked motors and the atleast one seal is common to each of the stacked motors.
 21. Thetransport apparatus of claim 17, wherein the at least one stator and theat least one rotor form a stack of motors and the at least one sealincludes a seal for each motor that is distinct from seals of othermotors in the stack of motors.
 22. The transport apparatus of claim 17,wherein the at least one salient stator pole extension and the at leastone rotor are positioned such that the at least one salient stator poleextension and the at least one rotor have an obstructionless interface.23. The transport apparatus of claim 17, wherein each stator andrespective rotor form a motor module configured to be stacked with othermotor modules.
 24. The transport apparatus of claim 17, wherein thedrive is configured as an axial flux flow drive or a radial flux flowdrive.
 25. The transport apparatus of claim 17, wherein the at least onerotor includes laminated salient poles.
 26. The transport apparatus ofclaim 25 wherein the at least one rotor includes a drive memberinterface, and the drive further includes a drive transmission memberinterfaced with the at least one rotor at the drive member interfacesuch that the drive transmission member interfaces with the laminatedsalient poles and fixes the laminated salient poles to the drivetransmission member.
 27. The transport apparatus of claim 26, whereinthe laminated salient poles are fixed to the drive transmission memberso that the laminated salient poles are arranged axially relative to thedrive transmission member.
 28. The transport apparatus of claim 26,wherein the laminated salient poles are fixed to the drive transmissionmember so that the laminated salient poles are arranged radiallyrelative to the drive transmission member.
 29. The transport apparatusof claim 17, wherein the at least one stator includes laminated salientpoles.
 30. The transport apparatus of claim 17, wherein the driveincludes a z-axis drive motor connected to the housing.
 31. Thetransport apparatus of claim 17, further comprising at least onereluctance based encoder track disposed on each of the at least onerotor and at least one reluctance based position feedback sensorconfigured to interface with the at least one reluctance based encodertrack.
 32. The transport apparatus of claim 17, wherein the at least onerotor is coupled to a coaxial drive shaft arrangement for driving the atleast one transport arm.
 33. A transport apparatus comprising: ahousing; a drive mounted to the housing; and at least one transport armconnected to the drive; where the drive includes at least one rotorhaving at least one salient pole of magnetic permeable material; atleast one stator including a stator core; a salient top plate; a salientbottom plate; and a coil unit associated with each salient top andbottom plate pair; where the salient top plate and salient bottom plateare connected to and spaced apart by the stator core and configured tointerface with the at least one salient pole of the at least one rotorto form a closed magnetic flux circuit between the at least one statorand the at least one rotor; and an isolation wall disposed between thetop plate and bottom plate where the isolation wall is configured toisolate the stator core from an isolated environment in which the atleast one transport arm operates.
 34. A transport apparatus comprising:a housing; a drive mounted to the housing; and at least one transportarm connected to the drive; where the drive includes at least onelaminated rotor having laminated salient poles of magnetic permeablematerial disposed in an isolated environment where the at least onelaminated rotor is isolated from the isolated environment; at least onestator having at least one salient pole with respective coil unitsdisposed outside the isolated environment such that the at least onesalient pole of the at least one laminated rotor and the salient pole ofthe at least one stator form a closed magnetic flux circuit between theat least one stator and the at least one rotor; and at least one sealconfigured to isolate the isolated environment.
 35. The transportapparatus of claim 34, wherein the at least one laminated rotor includesa drive member interface and the drive further includes a drivetransmission member interfaced with the at least one laminated rotor atthe drive member interface such that the drive transmission memberinterfaces with the laminated salient poles and fixes the laminatedsalient poles to the drive transmission member.
 36. The transportapparatus of claim 35, wherein the laminated salient poles are fixed tothe drive transmission member so that the laminated salient poles arearranged axially relative to the drive transmission member.
 37. Thetransport apparatus of claim 35, wherein the laminated salient poles arefixed to the drive transmission member so that the laminated salientpoles are arranged radially relative to the drive transmission member.38. The transport apparatus of claim 34, wherein the at least onelaminated rotor is embedded in an insulator that is configured toisolate the at least one laminated rotor from the isolated environment.39. The transport apparatus of claim 34, wherein the at least one sealis integral to the at least one stator.
 40. The transport apparatus ofclaim 34, wherein the at least one seal comprises a membrane mounted tothe at least one stator.
 41. The transport apparatus of claim 34,wherein the at least one seal depends from the at least one stator. 42.The transport apparatus of claim 34, wherein the at least one statorstructurally supports the at least one seal.
 43. The transport apparatusof claim 34, wherein the at least one seal conforms to a shape of the atleast one stator.
 44. The transport apparatus of claim 34, wherein theat least one stator includes a stator core, a top plate and a bottomplate where the top plate and bottom plate form a salient pole and areconnected to and spaced apart by the stator core and configured tointerface with the at least one laminated rotor, and the at least oneseal is between the top plate and bottom plate and configured to isolatethe stator core from an isolated environment in which the at least onetransport arm operates.
 45. The transport apparatus of claim 34, whereinthe drive further includes at least one salient stator pole extensiondisposed within the isolated environment and aligned with a respectivesalient pole of the stator, where the at least one seal is disposedbetween each salient pole of the stator and a respective salient statorpole extension.
 46. The transport apparatus of claim 45, wherein thedrive further includes a seal support member having an inner surfacedisposed in the isolated environment and an outer surface facing awayfrom the isolated environment, where the at least one seal is disposedon or adjacent the outer surface and the seal support surface isconfigured to structurally support the at least one seal.
 47. Thetransport apparatus of claim 46, wherein the seal support member isconfigured to house the at least one salient stator pole extension.